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Cold

The common cold, also known as the common cold, is one of the most common ailments affecting people around the world, especially during the autumn and winter periods. Although it is usually mild and resolves on its own, it can be bothersome, interfering with daily functioning, and in some cases can lead to complications. Understanding the causes, symptoms, treatments and prevention of the common cold, as well as the ability to distinguish it from the flu, is crucial for proper management and care of your own health and that of others.

Common cold: Definition, Causes and Differences from the Flu

Understanding the nature of the common cold starts with defining it, knowing the viruses responsible for causing it, and distinguishing it from the often confused flu.

What is a cold? Medical Definition

A cold is a set of clinical symptoms associated with a viral infection of the upper respiratory tract. This infection primarily affects the mucous membrane lining the nose, throat and paranasal sinuses. It is an extremely common disease – the average adult experiences it 2-3 times a year, while children get sick even more often.

Viruses That Cause the Common Cold: The Role of Rhinoviruses and Other Pathogens

More than 200 different types of viruses are responsible for the symptoms of the common cold. The most common cause, accounting for 40-50% of all cases, is rhinovirus (HRV). Rinoviruses belong to the Picornaviridae family and are small RNA viruses. They are characterized by the fact that they multiply best at a temperature slightly lower than the temperature inside the body, prevailing in the nasopharyngeal cavity (about 33°C), which explains why the symptoms are often most intense in this area.

In addition to rhinoviruses, other viruses can also cause the common cold, including:

• Coronaviruses (responsible for 10-15% of cases; these are common, seasonal coronaviruses, not SARS-CoV-2 causing COVID-19)
• Adenoviruses
• Parainfluenza viruses
• RSV (respiratory syncytial virus)
• Enteroviruses (e.g. Coxsackie viruses)
• Parvoviruses
• Sometimes even flu viruses can cause symptoms resembling a cold.

Such a large variety of viruses that cause the common cold has significant consequences. First, it prevents the creation of an effective, universal vaccine – unlike influenza, where the number of circulating strains is limited and a vaccine is developed every year that targets the most likely variants. Secondly, recovering from an infection caused by one type of virus (e.g. one of more than 100 rhinovirus serotypes) does not provide immunity to the others. This is why people get colds many times during their lives.

Colds vs. Flu: Key Differences in Symptoms and Course

The common cold is often confused with influenza, which is also a viral respiratory disease, but caused by other viruses – influenza A, B or, less commonly, C. Distinguishing between these two diseases is important because influenza is usually more severe and associated with a higher risk of serious complications, so it is worth knowing the treatments.

Here are the key differences:

• Onset of the disease: Symptoms of the disease may include a runny nose, sore throat, and cough. The common cold develops gradually, over 1-2 days. The flu strikes suddenly, often within a few hours.
• Fever: can last up to 7 days if you have a cold. In colds, fever is rare, and if it occurs, it is usually low (low-grade fever, below 38°C). Influenza is often accompanied by high fever (above 38°C, even 39-40°C) and chills.
• Muscle and joint pain: With colds, they are rare and mild. In the flu, they are common and strong, covering the entire body.
• Headache: In colds, it is rare and mild. In flu, it is frequent and strong.
• Fatigue and weakness: A cold is accompanied by mild to moderate fatigue. The flu causes significant weakness, a feeling of shattering and exhaustion that can persist even after other symptoms have subsided.
• Nasal symptoms (runny nose, stuffy nose): Very common and predominant symptoms of infection are cough and runny nose. in colds. In influenza, they occur less frequently or are less severe.
• Sore throat: A common, often one of the first symptoms of a cold. It is less common in influenza.
• Cough: It is common in colds, initially it may be dry, then often turns wet, associated with the flow of secretions. In the flu, it is frequent, usually dry, tiring, and may be accompanied by chest pain.
• Sneezing: Very common in colds. Rare in flu.
• Gastrointestinal symptoms (nausea, vomiting, diarrhoea): Very rare in adults with colds. In influenza they are also rare in adults, but may occur more often in children. It should be remembered that the so-called “stomach flu” is a completely different disease (gastroenteritis), not related to the flu virus.

Comparison table: Cold vs flu vs COVID-19 (Omicron variant)

Symptom	Cold	Influenza	COVID-19 (Omicron – typical course)
Beginning	Gradual	Sudden, violent	Gradual
Fever	Rare, low (<38°C)	Common, high (>38°C), chills	Often, it can be different
Muscle/joint pain	Rare, mild	Often, strong	Sometimes
Headache	Rare, mild	Often, strong	Often
Fatigue/Weakness	Mild/Moderate	Considerable, exhaustion	Often
Runny nose/stuffy nose	Very often, dominant	Less frequent, less severe	Often
Sore throat	Very often	Less	Very often
Cough	Often, it can be wet	Often, usually dry, tiring	Often, usually dry
Sneezing	Very often	Seldom	Sometimes
Loss of smell/taste	Seldom	Seldom	Sometimes (less often than with earlier variants)
Gastrointestinal symptoms	Very rare in adults	Rare in adults, more common in children	Seldom
Shortness of breath	Never (unless complications)	Rare (may be with complications)	Sometimes

It should be emphasized that the table above shows typical clinical pictures. However, the symptoms can overlap, and their severity varies from person to person. The Omicron variant of COVID-19 in particular often gives symptoms very similar to the common cold. This means that self-diagnosis based solely on symptoms is unreliable. In case of doubt, severe course of the disease or belonging to the risk group of complications, a medical consultation is necessary. Your doctor may order appropriate diagnostic tests (e.g. rapid antigen test or PCR swab for influenza or COVID-19) to make a confident diagnosis. Relying only on symptoms can lead to mistaken risk assessments and delays in the implementation of appropriate treatments, such as antiviral treatment for influenza or isolation for COVID-19.

Cold Symptoms: Diagnosis, Course and When to See a Doctor

Accurate recognition of symptoms, understanding the typical course of the disease and awareness of alarm signals are crucial for proper management during a cold.

Common Cold Symptoms: From Runny Nose to Fatigue

The symptoms of a cold, although usually mild, can be diverse and include:

• Runny nose (rhinitis): This is one of the most characteristic symptoms. Initially, the discharge is usually watery and transparent, accompanied by a scratchy or burning sensation in the nose. Over time, the runny nose thickens, becomes milky, yellowish or even greenish. It is important to remember that the color of the secretion does not indicate bacterial superinfection and is not an indication for antibiotic therapy. A thick runny nose causes a feeling of nasal congestion and makes it difficult to breathe. Smell may also be impaired.
• Sore throat: This is often one of the first signs of an approaching cold. It manifests itself as a feeling of scratching, burning or dryness. The throat may be reddened, and inflammatory papules may be visible on its posterior wall. Hoarseness may also appear.
• Cough: It does not always occur, but it is a common symptom. It usually appears a little later than a runny nose or sore throat. Initially, it is often dry and irritating, and then it can turn into a wet (productive) cough, associated with the flow of secretions from the nose and sinuses down the back of the throat and its production in the lower respiratory tract. Cough is the symptom that can last the longest, even for 2-3 weeks after other ailments have subsided.
• Sneezing: It is a common, reflex symptom of irritation of the nasal mucosa.
• General malaise, fatigue, weakness: Although not as severe as in the flu, the feeling of being “shattered” is typical of the common cold.
• Headache: It is less common than influenza and is usually mild. It may be related to a feeling of pressure in the sinuses caused by swelling of the mucous membrane.
• Muscle and osteoarticular pain: Like headaches, they are rare and mild.
• Low-grade fever or low fever: Fever above 38°C is rare in adults, but may be more common in children. It is usually a low-grade fever.
• Watery eyes: It can accompany runny nose and irritation of the mucous membranes.
• Other, less common symptoms: Depending on the type of virus, additional symptoms may appear, such as conjunctivitis (e.g. with adenovirus infection) or skin rash (e.g. with enterovirus).

Phases of the common cold: how do symptoms change over time?

A cold has its characteristic, although individually variable, course over time:

• Incubation period: The time from the moment the virus enters the body to the appearance of the first symptoms. It is usually 1 to 3 days. Some sources indicate 1-2 days. During this period, a person may already be infectious, although they do not yet have symptoms.
• Initial Phase (Days 1-3): The disease begins gradually. The first signs are often scratchy or sore throat, a feeling of dryness or discomfort in the nose, and general malaise. Then comes a runny nose and sneezing. The symptoms gradually increase.
• Peak Phase (Days 2-4): Symptoms reach their maximum intensity. The runny nose becomes thicker, the nose is one of the places where the symptoms of the disease are most common. Severely clogged, cough, headache and low-grade fever may appear. During this period, infectivity is at its highest.
• Resolution phase (from day 4-5): The symptoms begin to gradually ease. The swelling of the nasal mucosa decreases, the runny nose subsides, and the mood improves.
• Total duration: Most cold symptoms disappear within 7 to 10 days. Some sources give a shorter time, 5-7 days. As mentioned, the cough can last much longer, up to 2-3 weeks.

Some describe the course of the common cold, dividing it into phases based on the dominant physiological processes, such as the “vascular phase” (initial, with watery runny nose) and the “cellular phase” (with thickening secretions), but this is not a standard division in the medical literature.

Alarm signals: when do symptoms require medical consultation?

The common cold is usually a self-limiting disease, which means that the body can cope with it on its own without the need for specialized treatment. However, there are situations in which the symptoms should cause concern and prompt a visit to the doctor. These include:

• Prolonged duration: Symptoms persist for more than 10-14 days without visible improvement.
• Deterioration after initial improvement: The symptoms have begun to subside, but suddenly recur or intensify (e.g. reappearance of fever, worsening of cough, are typical symptoms of a cold.
• High Fever: The body temperature exceeds 38 degrees, which is one of the typical symptoms of a cold. 38°C – 38.5°C, persists for several days or does not decrease after administration of antipyretics.
• Severe Pain: This is especially true for persistent headache, severe pain in the sinus area, which can be symptoms of an infectious disease (forehead, cheeks, bridge of the nose, especially when bending) or severe ear pain.
• Respiratory symptoms: Shortness of breath, difficulty breathing, wheezing, tightness or chest pain, especially worsening when breathing or coughing.
• A severe or prolonged cough may be a symptom of a viral infection. Especially if it is a productive cough, with expectoration of thick, purulent (yellow, green) sputum, or if the cough is very tiring and persists for a long time. The appearance of hemoptysis is always an alarm signal.
• Other worrying symptoms: Significant weakness preventing daily functioning, stiff neck, impaired consciousness, delirium, severe dizziness, appearance of skin rash.
• Occurrence of symptoms in people in risk groups: Particular vigilance should be exercised when cold symptoms appear in small children (under 5 years of age), the elderly (over 65 years of age), pregnant women, and people suffering from chronic diseases (such as asthma, COPD, heart disease, diabetes) or who are immunocompromised. In these people, the risk of complications is much higher.

It is important to understand that the assessment of the need for a medical visit should take into account not only the list of symptoms, but also the individual context of the patient – their age, general health, comorbidities – and the dynamics of the disease – whether the symptoms disappear or worsen. Even a seemingly mild symptom, such as a cough, may require consultation in an infant or person with asthma, while in a healthy adult it will only be a temporary complaint.

How Does Infection Occur? Transmission Routes and Risk Factors

Knowledge of the transmission routes of cold viruses and factors that increase the risk of disease is crucial for effective prevention.

Transmission mechanisms of cold viruses

The viruses responsible for the common cold spread in several ways:

• The droplet route is one of the most common causes of colds. This is the main transmission mechanism. A sick person, when coughing, sneezing or even talking, releases small droplets of saliva and secretions from the respiratory tract containing viruses into the environment. People nearby can inhale these infectious droplets, leading to infection.
• Direct and indirect contact: Viruses can be transmitted through direct contact with a sick person, e.g. by shaking hands. The indirect contact route is equally important – viruses can settle on various surfaces and objects (door handles, handrails, telephones, keyboards, toys). If a healthy person touches such a contaminated surface and then touches their eyes, nose, or mouth before washing their hands, the virus can enter the body. Some viruses, like rhinoviruses, are relatively stable and can survive on surfaces for several hours, which increases the risk of transmission by this route.
• Oral route: For some viruses that can cause cold symptoms (e.g. adenoviruses, enteroviruses), oral (fecal-oral) transmission is also possible, but this is not a typical route for the common cold as a set of symptoms.

A sick person is most infectious within the first 2-3 days after the onset of symptoms, when the amount of virus in the secretions is the highest. However, the shedding of the virus can take up to 2 weeks, which means that the risk of infecting others persists for a longer period of time.

Factors that increase susceptibility to the disease

Not every contact with the virus leads to the development of the disease. Susceptibility to the disease depends on many factors:

• Seasonality: Colds occur most often in autumn and winter (from October to March or April) and early spring. This is facilitated by lower temperatures, changes in air humidity and spending more time indoors.
• Being in large groups of people: Places such as schools, kindergartens, nurseries, offices, public transport or shopping malls create ideal conditions for the easy spread of viruses through droplets and contact.
• Age: Children, especially in preschool and early school age, get sick much more often than adults. This is due to their immature immune system and frequent, close contacts with peers and not always developed hygiene habits. Older people (over 65 years of age) are also more susceptible to infections, and additionally at risk of a more severe course and complications.
• Immune System Status: Weakened immunity significantly increases the risk of developing the disease. Factors that weaken immunity include:
  • Chronic stress: The cortisol secreted then inhibits the activity of immune cells, making the body more susceptible to infections.
  • Sleep deprivation and fatigue: Lack of proper regeneration weakens the body’s defense capabilities.
  • Inadequate diet: Deficiencies of vitamins (especially D, C, A) and minerals (zinc, selenium) impair the functioning of the immune system.
  • Lack of regular physical activity: Moderate physical exercise strengthens immunity, while its lack weakens it.
  • Stimulants: Smoking and alcohol abuse negatively affect the body’s defense mechanisms.
  • Chronic diseases and immunocompromised conditions can increase the risk of viral infection, leading to more severe flu and cold symptoms. People with respiratory diseases (asthma, COPD), heart disease, diabetes, cancer, congenital or acquired immunodeficiencies (e.g. after chemotherapy, immunosuppressive treatment, HIV infection) and transplant patients are more likely to suffer from infections and their complications.
• Environmental factors: Sudden temperature fluctuations and low humidity can exacerbate the symptoms of the disease (e.g. in heated rooms in winter) can dry out the mucous membranes of the respiratory tract, making them more susceptible to the penetration of viruses.

The risk of contracting a cold is therefore the result of two main elements: exposure to the virus (which depends on the season, staying in crowded places and the level of hygiene in the environment ) and the individual susceptibility of the body in the context of flu and colds. (determined by age, immune status, lifestyle and comorbidities ). Effective prevention therefore requires action on both fronts – minimizing contact with the virus and strengthening one’s own defense mechanisms.

Relieving Cold Symptoms: Effective Methods and Home Remedies

Since there is no causal treatment for the common cold, the therapy focuses on alleviating the annoying symptoms and supporting the body in the fight against the infection.

Symptomatic Treatment Basics: Rest and Hydration

Two fundamental elements of managing a cold are rest and proper hydration. Although they do not significantly shorten the duration of the disease, they significantly improve well-being and support natural defenses.

• Rest: It is absolutely crucial. It allows the body to direct all its energy to fighting the virus. Physical and mental exertion should be avoided, and it is best to stay at home, which further reduces the spread of infection. Adequate sleep (7-8 hours) is recommended.
• Hydration: Drinking plenty of fluids is extremely important, especially if you have a low-grade fever. It is recommended to drink at least 2 liters of fluids a day. Proper hydration helps to keep the mucous membranes moist, which supports their defensive functions, and dilutes the thick secretion in the nose and respiratory tract, making it easier to remove. The best choice is water, but you can also drink warm herbal teas, natural fruit juices (diluted) or clear broths (e.g. broth).

Over-the-counter (OTC) medications: What to choose for specific symptoms?

Pharmacies offer a wide range of over-the-counter (OTC) medications that can help relieve individual cold symptoms. However, they should be used prudently and according to the recommendations.

• Analgesics and antipyretics:
  • Acetaminophen: It effectively reduces fever and relieves pain (e.g. headaches, throats). It is considered a relatively safe drug, as long as you do not exceed the recommended daily dose (usually 4g for adults). It has no anti-inflammatory effect. Attention should be paid to its presence in combination preparations to avoid overdose.
  • Non-steroidal anti-inflammatory drugs (NSAIDs): These include ibuprofen, naproxen, acetylsalicylic acid (aspirin). In addition to analgesic and antipyretic effects, they also have anti-inflammatory effects, which can be beneficial, for example, in the case of severe sore throat or muscle pain. It is important to remember about contraindications and possible side effects (e.g. stomach irritation – caution in peptic ulcer disease; effects on the kidneys). Aspirin is contraindicated in children under 12. years of age due to the risk of Reye’s syndrome.
• Nasal decongestants: They help reduce swelling of the nasal mucosa and make breathing easier.
  • Topical (drops, aerosols): They contain substances such as xylometazoline or oxymetazoline. They work quickly, bringing relief from nasal congestion. However, they should not be used for more than 5-7 days, as they can lead to the so-called drug-induced rhinitis (the “rebound” effect) and mucosal addiction.
  • Oral: They contain, for example, cold medicines that can relieve symptoms. pseudoephedrine. They have a systemic effect and may be more convenient to use. Caution should be exercised in people with heart disease, hypertension, hyperthyroidism. Pseudoephedrine is a common ingredient in combination preparations “for colds and flu”. Antihistamines have little effectiveness in clearing the nose during a cold.
• Medicines for sore throat: Available as lozenges, aerosols or fabric softeners. They may contain local anesthetics (e.g. lidocaine), anti-inflammatory substances (e.g. flurbiprofen, choline salicylate) or antiseptics (e.g. cetylpyridinium chloride, which is one of the medicines for colds). Just sucking on the lozenge stimulates saliva production, which moisturizes the throat and can bring relief.
• Cough suppressants and expectorants: The choice depends on the type of cough.
  • For dry cough (non-productive): Drugs that inhibit the cough reflex, such as dextromethorphan, butamirate or levodropropizin, are used. However, their effectiveness in relieving cold cough is sometimes limited.
  • For wet cough (productive): Expectorant drugs (mucolytics) are used, which dilute the thick secretion in the respiratory tract and facilitate expectoration. These include, for example, ambroxol, bromhexin, acetylcysteine, guaifenesin. Expectorants should be taken at least a few hours before bedtime (usually by 4:00-5:00 p.m.) so as not to intensify coughing at night.
• Combination preparations: These are popular medicines in the form of dissolving sachets or tablets, often advertised as “cold and flu” remedies. They usually contain a combination of several active substances, e.g. an analgesic/antipyretic (paracetamol or NSAID), a nasal decongestant (pseudoephedrine or phenylephrine), and sometimes an antihistamine (which can reduce runny nose but also cause drowsiness) or vitamin C. They may be convenient to use, but it is necessary to check the composition carefullyto avoid taking too much of a substance, especially if you are using other medications (e.g. extra paracetamol) at the same time.
• Supplements:
  • Vitamin C: Despite popular belief, there is a lack of strong scientific evidence that taking high doses of vitamin C shortens the duration or relieves cold symptoms in the general population. It may be of little importance in people who are subjected to heavy physical exertion or exposed to cold.
  • Zinc: Some studies suggest that zinc supplementation, started within 24 hours of the onset of symptoms, may slightly shorten the duration of the common cold. However, the evidence is inconclusive, and zinc can cause side effects (e.g. a metallic taste in the mouth).
  • Rutoside (rutin): It is often found in preparations with vitamin C. It is supposed to seal blood vessels, but there is no evidence of its effectiveness in treating the common cold.
  • Vitamin D: can support the immune system in fighting flu and colds. It plays an important role in the functioning of the immune system, and deficiencies are common, especially in autumn and winter. Vitamin D supplementation is important for infection prevention , but its role in treating the cold itself is less documented.

Proven home remedies for relieving ailments

In addition to OTC medications, there are many traditional home remedies that can provide relief from cold symptoms:

• Gargling: Gargling with a saline solution (half to one teaspoon of salt per glass of warm, boiled water) several times a day can help reduce swelling and clear the throat of secretions. You can also use infusions of herbs with astringent and anti-inflammatory properties, such as sage or chamomile.
• Honey: It has properties that soothe an irritated throat and may help relieve cough, especially in children over 1 year of age (studies indicate that it can be as effective as some cough syrups). Honey also has some antibacterial properties. It can be added to warm (but not hot, so that it does not lose its properties) tea or water with lemon. Note: Honey must not be given to infants under 1. years of age due to the risk of childhood botulism.
• Steam inhalations (“steamers”): Inhalation of water vapor perfectly moisturizes the dry mucous membranes of the nose and throat, dilutes thick secretion and facilitates its removal, bringing relief from nasal congestion and cough. You can inhale just the steam from a bowl of hot water (be careful not to burn yourself) or use an inhaler. You can add saline (0.9% NaCl) or a few drops of essential oils, e.g. eucalyptus, pine, mint, thyme or tea tree oils. However, caution should be exercised as essential oils can irritate the respiratory tract, especially in young children and people with asthma.
• Air humidification: Dry air, especially during the heating season, additionally dries out and irritates the mucous membranes. It is worth taking care of the appropriate humidity in the rooms by using air humidifiers or simpler methods, such as putting wet towels on radiators or placing dishes with water.
• Hot drinks: Drinking warm liquids has a soothing effect on a sore throat, warms you up and helps you hydrate. Cold medications are recommended to relieve symptoms.
  • Tea: Especially herbal, such as linden or elderberry, which have diaphoretic properties and can help reduce fever. Chamomile or sage tea also has a soothing effect on the throat.
  • Chicken soup: A traditional home remedy that not only warms up and provides fluids and electrolytes, but the ingredients it contains (e.g. cysteine) can have a slight anti-inflammatory effect and facilitate the removal of mucus.
  • Warm milk with honey and garlic: A popular “grandma’s” way, although it should be remembered that there is a contraindication to giving honey to babies.
  • Juices: Warm raspberry, elderberry or blackcurrant juice provides vitamins and has a warming effect.
• Natural ingredients with supportive effects:
  • Garlic: Known as a “natural antibiotic” due to its content of allicin, a compound with antiviral and antibacterial properties. It is best eaten raw, e.g. by adding it to dishes or preparing syrup. Unscented preparations in capsules are also available.
  • Ginger: It has a strong anti-inflammatory and warming effect. Fresh ginger root can be added to tea, infusions or dishes.
  • Onion: Like garlic, it contains sulfur compounds with antimicrobial activity. Onion syrup is popular (onion covered with sugar releases juice), traditionally used for coughs.
  • Herbs: In addition to the aforementioned linden, elderberry, chamomile and sage, thyme (expectorant), purple coneflower (Echinacea), which can stimulate the immune system, especially if applied at the very beginning of an infection, and willow bark, containing natural salicylates, with anti-inflammatory and antipyretic effects, can also be used in folk medicine as one of the remedies for colds.
• Nasal/sinus irrigation (irrigation): Using special irrigation bottles or kits with saline solution or ready-made sea salt solutions helps to mechanically clean the nasal cavities and sinuses of residual secretions and allergens, which brings relief from runny nose and the feeling of congestion, it is worth using lozenges.
• Warm compresses and baths: A warm bath or shower can help relax your muscles and relieve the feeling of being shattered. Warm compresses on the chest can relieve coughing. Soaking your feet in warm water with salt is a traditional method of warming up the body. With fever, cold medication can bring relief. cool compresses on the forehead or neck.

Why do antibiotics not work for colds?

This is one of the most important pieces of information to understand and remember: antibiotics are completely ineffective in treating the common cold. This is due to the fundamental difference between viruses and bacteria:

• The common cold is caused by VIRUSES.
• Antibiotics are drugs that act only on BACTERIA, killing them or inhibiting their multiplication. Their mechanism of action is directed at structures or metabolic processes characteristic of bacterial cells (e.g. cell wall structure, bacterial protein synthesis), which viruses do not have.
• Viruses have a completely different structure and life cycle – they multiply inside the host cells, using its mechanisms. Antibiotics have no effect on them.

The use of antibiotics in the case of a viral infection, such as the common cold, is not only pointless (it does not shorten the duration of the disease, does not alleviate the symptoms ), but it is even harmful:

• It contributes to the growth of antibiotic resistance: Any unjustified use of an antibiotic exposes bacteria (both pathogenic and those constituting the natural flora of the body) to its action, which promotes the selection and multiplication of resistant strains. Antibiotic resistance is one of the biggest global threats to public health today, as it leads to situations where even simple bacterial infections become difficult or impossible to treat.
• It exposes the patient to side effects: Antibiotics, like any medication, can cause side effects such as diarrhea (resulting from the destruction of beneficial intestinal flora), nausea, vomiting, allergic reactions (rashes and even anaphylactic shock), mycoses.
• It generates unnecessary costs.

It should be emphasized that even a purulent (yellow or green) runny nose is not automatically a sign of a bacterial infection and is not an indication for antibiotic administration. The change in the color of the secretion is a natural stage of the body’s inflammatory response.

Antibiotics are life-saving drugs, but their use must be limited to when they are actually needed, i.e. to treat bacterial infections confirmed by a doctor. In the context of the common cold, an antibiotic may only be recommended if you develop a secondary bacterial superinfection, such as bacterial sinusitis, bacterial otitis media or bacterial pneumonia. The decision to include an antibiotic is always made by a doctor based on clinical evaluation and possible additional tests.

Educating patients about the viral nature of the common cold and the pointlessness of using antibiotics in this situation is crucial. Giving up unnecessary antibiotic therapy is not only a matter of individual health, but also an expression of social responsibility in the fight against the global problem of antibiotic resistance.

Prevention of colds: how to effectively protect yourself from infection?

While it can be difficult to avoid catching a cold altogether due to the prevalence of viruses, there are many effective strategies that can significantly reduce your risk of getting sick. Prevention is based on three main pillars: hygiene, avoiding exposure and strengthening immunity.

Hygiene as the Key to Prevention: Hand Washing and Other Rules

Proper hygiene, especially hand hygiene, is considered to be the basic and one of the most effective methods of preventing the spread of infections, including the common cold. Hands are the main route of transmission of microorganisms – we touch various surfaces with them and then unknowingly touch our faces, allowing viruses to enter the body.

• Frequent and correct hand washing:
  • When to wash? Always after returning home, before preparing and eating meals, after using the toilet, after contact with a sick person, after blowing your nose, coughing or sneezing, after contact with animals, after touching surfaces in public places (door handles, handrails, elevator buttons).
  • How to wash? Use water and soap (preferably liquid, as bar soap can harbor bacteria). Washing should take at least 30 seconds, and according to the recommendations of the WHO and GIS for hygienic hand washing – 40-60 seconds. It is crucial to thoroughly wash all surfaces of the hand: the inner and back sides, the space between the fingers, thumbs, fingertips and nails (rubbing them on the inside of the other hand) and wrists. After washing, hands should be thoroughly rinsed under running water and dried with a disposable paper towel. In public places, it is a good idea to use a paper towel to turn off the tap and open the door to avoid contaminating your hands again.
• Hand disinfection: When access to water and soap is impossible, an effective alternative is to use an alcohol-based hand sanitizer (minimum 60%). The preparation should be applied to dry hands and thoroughly rubbed into all surfaces of the hands (according to the washing schedule) until completely dry (approx. 30 seconds). Disinfection is not a substitute for washing if your hands are visibly dirty.
• Cough and sneeze hygiene (“respiratory etiquette”): When coughing or sneezing, cover your mouth and nose with a tissue, which should then be immediately disposed of in a closed bin. If you don’t have a tissue, cough or sneeze into the crook of your elbow, not into your hands.
• Avoiding touching your face: Try not to touch your eyes, nose and mouth with unwashed hands, as these are the main gates for viruses to enter.
• Surface cleaning and disinfection: Regular cleaning and, if necessary, disinfection of frequently touched surfaces in your home and workplace (door handles, light switches, telephones, keyboards, countertops, toys) can help reduce the spread of viruses.
• Ventilation of rooms: Opening windows regularly, even briefly in winter, ensures air exchange and helps to reduce the concentration of viruses indoors.

Avoiding Virus Exposure

Limiting contact with viruses is another important element of prevention:

• Avoiding close contact with people with the disease: Keep your distance from people who show symptoms of a cold or flu. Avoid shaking hands, hugging, kissing to reduce the risk of viral infection.
• Avoiding large gatherings of people: During the season of increased illness, it is worth avoiding crowded places such as shopping malls, cinemas or public transport during rush hours, as much as possible.
• Staying at home in case of illness: People who get sick themselves should stay at home to rest and not infect others in the workplace, school or public places.

Boosting Immunity: The Role of Diet, Sleep, and Lifestyle

A strong immune system is better equipped to fight viruses. It can be supported by a healthy lifestyle:

• Healthy, balanced diet: It should be rich in vegetables, fruits, whole grains, lean protein, and healthy fats. It provides essential vitamins, minerals and antioxidants that support immune function. Particularly important are:
  • Vitamin C: It is found in citrus, peppers, broccoli, parsley, berries.
  • Vitamin D: Crucial for a normal immune response. Its main source is skin synthesis under the influence of the sun, which is why supplementation is often recommended in autumn and winter in Poland.
  • Vitamin A: It is important for the health of the mucous membranes, which are the first line of defense.
  • Zinc: It affects the production and activity of immune cells. Good sources are nuts, pumpkin seeds, seeds, whole grains, meat.
  • Selenium: It supports the immune system and has antioxidant properties. It is found, m.in, in Brazil nuts, fish, eggs, which are a source of ingredients that support the immune system in the fight against viruses that cause colds.
  • Antioxidants: They fight free radicals, protecting immune cells. Berries, dark leafy vegetables and green tea are rich in them.
• Regular physical activity: can help boost immunity and reduce the risk of flu and colds. Moderate physical exercise (e.g. 30 minutes of brisk walking, cycling, swimming) performed regularly strengthens the immune system. However, overtraining, which can weaken immunity, should be avoided.
• The right amount and quality of sleep: Sleep is crucial for the regeneration of the body and the proper functioning of the immune system. 7-8 hours of sleep per night is recommended for adults.
• Coping with stress: Chronic stress weakens immunity. Relaxation techniques (e.g. yoga, meditation, deep breathing), hobbies, spending time in nature can be helpful.
• Adequate hydration: Drinking enough water (about 2 liters a day) is important not only during illness, but also on a daily basis, to maintain the proper functioning of the body, including mucous membranes.
• Avoiding stimulants: Smoking damages the mucous membrane of the respiratory tract and weakens immunity. Alcohol abuse also negatively affects the immune system.
• Preventive vaccinations: they are crucial in preventing flu, but they will not cure the common cold. Although there is no vaccine against the common cold, it is very important to get an annual flu vaccination. It helps to avoid or alleviate the flu and thus prevent serious complications. COVID-19 vaccinations are also recommended.

It is worth remembering that individual prevention methods work best when used together. Hygiene alone may not be enough if our immunity is weakened by lack of sleep or stress. On the other hand, even a strong immune system can become infected with very high exposure to the virus. Therefore , the most effective strategy is to combine hygiene, avoiding unnecessary risks and systematically strengthening immunity through a healthy lifestyle.

6. Possible complications after a cold: what to look out for?

Although the common cold is usually a mild illness, it can sometimes lead to complications, especially if it is left untreated, underestimated, or occurs in people at risk. The most common complications are secondary bacterial infections.

Secondary bacterial infections: when a virus paves the way for bacteria

A viral infection, such as the common cold, causes inflammation and damage to the mucous membrane of the airways. This weakens natural defense mechanisms (e.g. the movement of cilia that clear the airways) and can create conditions conducive to the multiplication of bacteria that normally live in the respiratory tract or have entered there from the outside. The most common bacterial complications include:

• Acute bacterial rhinosinusitis: This is one of the most common complications of the common cold. Viral inflammation and swelling of the mucous membrane can block the narrow sinus openings to the nasal cavity, leading to mucus retention and bacterial multiplication. Symptoms suggestive of bacterial superinfection include: worsening or recurrence of symptoms (e.g. headache, runny nose, fever) after initial improvement, thick, purulent (yellow, green) nasal discharge, often with an unpleasant smell, severe pain or a feeling of pressure in the sinus area (forehead, cheeks, bridge of the nose), which intensifies when the head is tilted forward, high fever, deterioration of the sense of smell, sometimes pain in the upper teeth. Untreated or recurrent sinusitis can become chronic (lasting more than 12 weeks) and lead to serious, although rare, orbital complications (e.g. orbital abscess) or intracranial complications (e.g. meningitis, brain abscess).
• Acute otitis media: This complication is particularly common in young children. It results from the transmission of the infection from the nasopharynx to the middle ear through the eustachian tube (Eustachius), which in children is shorter, wider and more horizontally arranged than in adults. Swelling of the mucous membrane blocks the tube, causing fluid to build up in the eardrum and cause bacteria to multiply. Symptoms include: sudden, severe, throbbing ear pain, deterioration of hearing, fever, feeling of fullness in the ear. In young children, it can manifest itself as irritability, crying, rubbing the ear, sleep and eating problems. Sometimes there is spontaneous perforation of the eardrum and leakage of purulent discharge from the ear.
• Bronchitis: A viral infection can go lower, to the bronchi, causing them to become inflamed. Sometimes bacterial superinfection occurs. The main symptoms are an increased cough, which may initially be dry and then becomes productive, with coughing up mucous or purulent sputum, fever, malaise, sometimes chest pain behind the sternum, and wheezing or whirring sounds heard when breathing.
• Pneumonia: It is a serious complication, less common than bronchitis, but especially dangerous for the elderly, young children and people with chronic diseases. It can be caused by bacteria that have multiplied in the body weakened by the virus. Symptoms include high fever, chills, severe cough (often with expectoration of purulent, sometimes blood-stained sputum), chest pain that intensifies when breathing and coughing, shortness of breath, rapid breathing and heart rate, and significant weakness. Pneumonia requires diagnosis (usually a chest X-ray) and antibiotic treatment, often in a hospital setting.
• Other complications: A cold can also lead to tracheitis (manifested by barking cough and pain behind the breastbone) or exacerbation of existing chronic respiratory diseases such as bronchial asthma or chronic obstructive pulmonary disease (COPD).

It is worth noting that many of these complications are due to the anatomical continuity of the airways. Inflammation and infection can easily “pass” from the nose and throat (the original site of viral infection) to adjacent structures – the paranasal sinuses (connected to the nasal cavity), the middle ear (connected to the nasopharynx by the eustachian tube) and to the lower respiratory tract (larynx, trachea, bronchi and lungs). Understanding this continuity helps explain why these complications are the most common.

Risk groups: Who is most at risk of complications?

The risk of complications after a cold is not the same for everyone. There are groups of people who are particularly vulnerable to them:

• Infants and young children (under 5 years of age, and especially under 2 years of age) – due to the immaturity of the immune system and narrower airways.
• Older people (over 65 years of age) – due to natural age-related weakening of immunity (immunosenescence) and a higher incidence of comorbidities.
• Pregnant women – due to changes in the functioning of the immune system during this period.
• People with chronic respiratory diseases such as bronchial asthma or COPD.
• People with other chronic diseases, e.g. heart disease, kidney failure, diabetes.
• People with immunodeficiencies, both congenital and acquired (e.g. cancer patients undergoing chemotherapy, organ transplant patients taking immunosuppressive drugs, people infected with HIV).
• Tobacco smokers – smoking damages the defense mechanisms of the respiratory tract.

In people from these groups, even a common cold should be treated with more attention, and any alarming symptoms should prompt a quick medical consultation.

Summary

The common cold is a common viral infection of the upper respiratory tract, most often caused by rhinoviruses, but also by many other types of viruses. Although it usually has a mild, self-limiting course lasting 7-10 days, its symptoms – such as runny nose, sore throat, cough or fatigue – can be bothersome. It is crucial to distinguish between a cold and flu, which has a sudden onset, a more severe course and is associated with a higher risk of complications.

Treatment of colds is only symptomatic and is based on rest, proper hydration and, if necessary, the use of over-the-counter medications to alleviate specific ailments (pain, fever, runny nose, cough). Proven home remedies such as inhalation, gargling with salt or drinking warm drinks with honey or ginger can also help. It should be strongly emphasized that antibiotics are ineffective in treating the common cold because they act on bacteria, not viruses. Their unjustified use contributes to the growth of the dangerous phenomenon of antibiotic resistance.

The best strategy to fight the common cold is prevention. It is based on following the rules of hygiene (especially frequent hand washing), avoiding close contact with sick people and taking care of the overall immunity of the body through a healthy diet, regular physical activity, adequate sleep and stress management.

In most cases, the cold passes without consequences, but it is important to remember about the possibility of complications such as sinusitis, middle ear or bronchitis, especially in people in risk groups. In the event of alarming symptoms (high fever, severe pain, shortness of breath, deterioration of the general condition) or prolongation of the disease, medical consultation is necessary.