Brief overview
- Description: Infection of the upper respiratory tract (especially nose, throat, bronchi), triggered by many different viruses
- Difference between cold/flu: Cold: gradual onset (scratchy throat, runny nose, cough, no or moderate fever), flu: rapid progression (high fever, aching limbs, severe feeling of illness)
- Symptoms: Sore throat, cold, cough, possibly slight fever, listlessness, headache
- Causes: numerous types of viruses; higher risk of illness in dry air, cold, weakened immune system
- Treatment: alleviation of symptoms with nasal drops, antipyretic medication, cough suppressants, inhalation, rest; causal treatment not possible
- Prognosis: usually unproblematic course lasting around one week, sometimes complications and secondary infections (sinusitis, middle ear infection, pneumonia); inflammation of the heart possible, especially in the case of overexertion
Common cold: Description
A cold (flu-like infection) is an infection of the upper respiratory tract. It can be caused by various types of cold viruses, which are also constantly changing. They mainly affect the mucous membranes of the nose, throat and bronchial tubes. A cold is very contagious and therefore common: schoolchildren catch a cold around seven to ten times a year, adults around two to five times.
Flu and the common cold – the differences
Many people confuse a cold (flu-like infection) with the flu. However, the real flu (influenza) is caused by other types of viruses (influenza viruses) and is usually much more severe than a cold. It can be life-threatening for older, immunocompromised or chronically ill people.
The symptoms of flu and the common cold overlap to some extent. But there are also characteristic differences:
- Progression: With a cold, the symptoms often develop gradually over several days. With the flu, the symptoms usually come on very suddenly and with full force.
- Fever: With a cold, the temperature often remains normal or only rises slightly. Fever is rare. With flu, the temperature usually rises quickly to over 39 degrees (high fever).
- Runny nose: A severe runny nose is typical of colds. Flu patients only sometimes have a runny nose.
- Cough: A severe, agonizing, dry, irritating cough is common with flu and can also be very painful. With colds, coughing often occurs later and is then less pronounced.
- Pain in the limbs: With flu, the pain in the limbs is much more severe than with a cold. This is often accompanied by muscle pain.
- Headaches: Headaches also differ between colds and flu. With a cold, they are less severe and more dull. Flu patients often suffer from severe headaches.
- Sweating and shivering: Generally, sweating and shivering are less pronounced with a cold; with flu, they accompany the fever.
- Duration of illness: A cold is usually over after a week. With the flu, it can sometimes take several weeks for those affected to fully recover.
Allergy or cold?
The symptoms of allergies and colds are often very similar. Allergies can also cause a runny nose, stuffy nose or sneezing. But there are differences.
- In the case of an allergy, the eyes are often irritated and sneezing attacks occur more frequently.
- Coughing, hoarseness and fever indicate a cold.
- In addition, patients with an allergy often do not feel as ill as people with a cold.
- An allergic rhinitis occurs very quickly after contact with the trigger. With a cold, the symptoms develop gradually.
Common cold: symptoms
A cold usually begins with a scratchy throat, followed by a cold or blocked nose. From the nasopharynx, the viruses travel further down into the bronchial tubes. The pathogens can also enter the paranasal sinuses and cause sinusitis.
Common cold: symptoms in the early stages
Viruses that trigger a cold usually enter the body via the mucous membranes of the nose or throat. This is why the first signs of a cold appear here.
Sore throat
A sore throat is usually the first symptom of a cold. It usually lasts no longer than two to three days.
If the sore throat persists beyond this period, it may be a bacterial inflammation of the tonsils (tonsillitis). You should then consult a doctor. Chills or headaches and aching limbs often occur in the first few days.
Runny nose and blocked nose
Inflammation of the nasal mucous membranes (rhinitis) is typical of a cold: the nose swells up, is blocked and can tickle or burn. When blowing the nose, clear-white, watery secretions come out at first. Later it becomes more viscous. Yellowish to greenish mucus forms, especially if bacteria are involved. These symptoms reach their peak on the second day after the onset of the cold.
Nosebleeds
Nosebleeds can occur in the course of a cold. This is because, on the one hand, the nasal mucous membranes are irritated by the virus. On the other hand, high pressure builds up in the nose when you blow your nose. Both can easily lead to a small blood vessel in the nose bursting.
Frequent nosebleeds can also indicate high blood pressure, abscesses or even malignant tumors in the nose. If you still suffer from recurring nosebleeds after a cold, you should be examined by a doctor.
Diarrhea and nausea
Slight nausea is normal with a cold, as is diarrhea. However, if nausea and diarrhea persist over a longer period of time during a cold, you should see a doctor. He or she can carry out further tests and prescribe antibiotics if you have a bacterial infection.
To avoid exacerbating symptoms such as nausea and diarrhea when you have a cold, you should avoid fatty foods and drinks (such as cocoa), yogurt, ice cream, sweets, caffeine and alcohol. It is best to drink tea, water and broth and eat dry foods such as bread, rice, potatoes, rusks or rolls.
The common cold: symptoms as it progresses
Additional symptoms occur as the cold progresses.
Weakness and feeling ill
Fever
In some people, the common cold is accompanied by a high temperature (from 37.5 degrees) or fever (from 38.1 degrees). Fever is the body’s defense reaction to the infection. Tolerating a slight fever can promote the healing process. However, a high fever is more debilitating, as the body consumes more oxygen and energy. You can alleviate it with fever-reducing medication or calf compresses.
Pain in the limbs and back
A cold is often accompanied by aching limbs, which can also manifest itself in the form of back pain.
Severe back pain can also be caused by a cold-related inflammation of the pleura (pleurisy). If the back pain persists after the general cold symptoms have subsided, you should consult a doctor.
Cough
As the illness progresses, symptoms such as a dry cough, a chesty cough or hoarseness also occur. They usually disappear again after a few days. If they persist for longer than two weeks, you should consult a doctor.
Voice gone?
A small proportion of cold sufferers lose their voice during the course of the illness. This can be indicated by a scratchy and raspy feeling in the throat. In most cases, those affected can only speak with difficulty, and sometimes not at all.
If you lose your voice completely when you have a cold, you should definitely see a doctor. Untreated laryngitis can cause permanent damage to the vocal cords and larynx. Children in particular need to be treated quickly. A threatening pseudocroup can develop in them.
Sweating with a cold
Excessive sweating is also common with colds. Most patients sweat mainly at night. However, sweating can also occur very suddenly during the day, especially during physical activity.
Dizziness with a cold
Dizziness often accompanies sweating with a cold. Dizziness also often occurs with a cold when a middle or inner ear infection is also present. However, dizziness can also indicate organ involvement, for example pneumonia or myocarditis. In this case, a visit to the doctor is necessary.
Pressure on the ears with a cold
Earache with a cold
Earache with a cold is rather unusual. If they do occur, viruses or – as part of a secondary infection – bacteria have migrated up from the mucous membranes in the nasopharyngeal area.
A painful middle ear infection occurs mainly in children and adolescents. In adults, however, it is rather rare. In some cases, pus collects in the middle ear, which makes the earache even worse.
If you suspect you have a middle ear infection, you should see a doctor. If the infection is not treated or treated incorrectly, it can spread further and even cause hearing damage.
Loss of smell and taste with colds
No taste? This phenomenon is not uncommon with colds. The reason is usually a blocked, irritated nose – because the flavors of food are perceived primarily through the nose. The tongue itself only recognizes sweet, sour, salty, bitter and spicy (umami). When the nasal mucosa recovers, the taste sensation normally returns.
However, in individual cases where the olfactory nerves are affected, it can take weeks or months for them to fully recover. Very rarely, the sense of taste and smell may not return at all.
Common cold: symptoms of complications
Symptoms of sinusitis
If you have a toothache when you have a cold, it is usually not caused by your teeth. Instead, it is often caused by an infection of the sinuses. In this case, the cold viruses have spread there or other types of virus have infected the sinus mucosa. A bacterial superinfection is also possible. The area above the teeth usually hurts, which can easily be mistaken for toothache. Other common symptoms of sinusitis are a purulent nasal discharge and a feeling of pressure in the sinus area.
Symptoms of tonsillitis
If inflammation of the tonsils accompanies the common cold, symptoms such as difficulty swallowing and pain in the throat and when speaking may occur. The tonsils are reddened and swollen. Bad breath also frequently develops.
Symptoms of bronchitis and pneumonia
Bronchitis or even pneumonia may develop in the course of a cold. Symptoms then include a severe cough, fever or diffuse back pain.
Neck pain
Neck pain is often added to the classic symptoms of a cold. It is not primarily caused by the virus, but rather arises because the whole body tenses up. Particularly in the case of severe aching limbs, headaches or toothache, this is caused by the body adopting a relaxed posture. In order to relieve the other parts of the body, especially the head, the neck muscles often tense up considerably.
In addition, the immune cells themselves cause pain. They release certain messenger substances that irritate the nervous system. Neck pain, as well as general headaches and aching limbs, therefore indicate that the infection is being actively fought.
Spread cold: symptoms
It can be dangerous if you do not take it easy during the acute phase of the cold. A protracted cold means that you have not completely got rid of the cold.
The main sign of a protracted cold is the time factor: if the symptoms of a cold do not subside after around a week, or after ten days at the latest, it is probably a protracted cold.
Yellow-green mucus formation indicates a secondary infection
Sinusitis
If a headache occurs during a cold, this is often a sign that the paranasal sinuses are involved (e.g. sphenoid sinusitis and frontal sinusitis).
Another sign of a protracted cold with complications in the paranasal sinuses – more precisely the maxillary sinuses – is jaw pain: colds and flu are not normally accompanied by a sore jaw – unless the mucous membrane of the maxillary sinuses has also become inflamed. In addition to viruses, bacteria can also cause sinusitis.
Common cold: causes and risk factors
A flu-like infection can be triggered by over 200 different types of viruses, including in particular
- Rhinoviruses (responsible for around 40 percent of all colds)
- RSV (responsible for 10 to 15 percent)
- Coronaviruses (responsible for 10 to 25 percent)
After rhinoviruses, the human metapneumovirus (HMPV) is the most common cause of colds in young children.
Droplet and smear infection
The viruses are transmitted to other people in small droplets of saliva produced when speaking, coughing or sneezing (droplet infection).
Once the viruses have entered the body, they first infect the mucous membranes of the nose and throat, and later also those of the bronchi and possibly the paranasal sinuses.
Virus strains that cause a cold mutate easily. This means that you are not necessarily immune to a particular virus after a single infection. You can catch it again and again.
Incubation period
There are usually around two to four days between infection and the onset of a cold (incubation period). During this time, no symptoms of illness appear, although the viruses are already in the body. Even without symptoms, you can infect other people during this time.
Colds caused by the cold?
The connection between cold and colds is discussed time and again. In the past, it was assumed that prolonged exposure to the cold alone could cause a cold. However, it is more likely that prolonged exposure to the cold weakens the immune system and viruses can penetrate the body more easily as a result. In addition, the mucous membranes (e.g. in the nose) are stressed by dry heating air and have less blood flow in the cold. This makes them more susceptible to infections.
You can find detailed information on how to prevent a flu-like infection in the article “Preventing a cold”.
Cold in summer?
Risk factors for catching a cold in summer are large temperature fluctuations as well as physical exertion and long periods in the sun, which stress the immune system. Staying in cool water for too long or wearing wet swimwear for too long also puts a strain on the immune system.
Colds: examinations and diagnosis
The doctor will diagnose a cold or flu-like infection based on the symptoms and a physical examination.
However, you don’t necessarily have to see a doctor if you have a cold. You can also cure a mild cold yourself.
When to see a doctor with a cold?
A visit to the doctor is advisable if you experience symptoms that are not typically associated with a cold. These include feeling very ill and having a high temperature. You should also see a doctor if a flu-like infection is accompanied by symptoms such as chest pain, severe earache or complete loss of voice. The same applies if you feel progressively worse, if the cold symptoms last longer than usual or if you experience symptoms that you have never had before with a flu-like infection.
In addition, the following groups of people should always consult a doctor, as even a simple cold can be dangerous for them:
- People with other existing illnesses (especially bronchial asthma or COPD as well as blood and heart diseases)
- People who have recently traveled abroad
- Elderly people
- Infants and small children
Medical history by the doctor
The doctor will first take your medical history (anamnesis). This gives you the opportunity to describe your symptoms in detail. The doctor may also ask questions such as:
- How long have you had these symptoms?
- Do you also have chills?
- Is the mucus when coughing or the nasal discharge greenish, yellowish or brownish?
- Do you have a high temperature or fever?
Physical examination
This is followed by a physical examination. The doctor will listen to your lungs (auscultation) in order to rule out other illnesses that could be caused by a cold (e.g. pneumonia).
Flu or cold?
It is important to determine exactly whether you have a cold or genuine flu. As mentioned above, flu is usually much more severe than a normal cold. It can even be life-threatening for young children, older people and people with a weakened immune system.
Common cold: Treatment
With or without medication, it usually takes about a week to get over a cold. Special active ingredients that directly combat the cold viruses and shorten the duration of the illness are not used. Antibiotics do not help against the viruses – only against additional bacterial infections.
So even if it is not possible to treat the cause of a cold, there is a lot that can be done to alleviate cold symptoms:
- Take it easy: If you take it easy physically, you take the strain off your ailing body. This also reduces the risk of the virus spreading in the body and affecting the lungs, ears or even the heart. Last but not least, physical rest can also help to prevent additional infections with other viruses or bacteria.
- Drink plenty of fluids, take care of your mucous membranes: If you have a cold, you should drink plenty (e.g. water, herbal teas) and soothe and care for the mucous membranes in the nasopharyngeal area, for example with inhalation, a seawater nasal spray – or decongestant nose drops if necessary (only use for a short time to avoid side effects!).
- Avoid tobacco and other irritants: To avoid aggravating cold symptoms, you should avoid tobacco and other throat irritants. The throat often reacts sensitively, even weeks after the cold.
You should also pay attention to hygiene to avoid infecting others with your cold. This means: don’t cough and sneeze into your hand, but into the crook of your arm. Wash your hands thoroughly after blowing your nose and dispose of tissues after one use. You can also wear a face mask if necessary. This will prevent you from infecting others around you.
You can read more detailed information on how to treat a cold in the article “What helps with a cold?”
Home remedies for a cold
There are also a number of home remedies that can alleviate the symptoms of a cold. You can find out what these are and how to use them correctly in the article “Home remedies for colds”.
A cold during pregnancy
Catching a cold during pregnancy is not uncommon. You can find out what you need to bear in mind in the article “Colds during pregnancy”.
Common cold: course of the illness and prognosis
A cold is usually harmless. Severe cases are the exception rather than the rule. However, secondary infections or complications can occur, especially if you do not cure yourself properly.
Duration of colds
The cold can also spread more easily if you do not take sufficient rest. The already weakened body is then particularly susceptible to secondary infections.
Viruses mutate very quickly. However, the body only forms special antibodies against the type of virus that has currently infected the body during a cold. If another or mutated cold virus is added, there is a risk of a new or further outbreak of illness.
You can find more detailed information on the duration of colds in the article “Flu infection: duration”.
Chronic colds
There is no such thing as a chronic cold in the true sense of the word. However, some patients catch new colds at short intervals or suffer from particularly persistent colds. This includes, among others:
- older patients
- People with various chronic pre-existing conditions
- People who have to take immunosuppressive medication (immunosuppressants)
Even if a person with a cold does not recover properly, the illness will drag on. In the case of a protracted cold, the pathogens in the body are not completely eliminated by the immune system. The person affected then has a cold practically all the time. So taking it easy is important!
Chronic colds
Doctors refer to a chronic cold as chronic inflammation of the nasal mucosa. Possible causes are
- Excessive use of nasal sprays or nasal drops (causes chronic swelling of the nasal mucosa)
- Allergies: Sometimes chronic rhinitis turns out to be an allergic reaction to house dust mites, for example.
- Granulomatosis with polyangiitis (formerly: Wegener’s disease): A constantly runny or chronically blocked nose with bloody nasal secretions and brownish crusts in the nose can indicate this chronic inflammatory disease of the blood vessels.
- Pollutants/irritants: Pollutants such as tobacco smoke, exhaust fumes and drugs can irritate the nasal mucosa and damage it to such an extent that it becomes persistently inflamed.
Persistent rhinitis can also occur during pregnancy and as a side effect of some medications (blood pressure medication).
Complications and secondary infections
Complications rarely occur with a cold. Sometimes the viruses can spread, infect other parts of the body and cause serious illnesses.
Sport with a cold is risky
Do not do any sport if you have a cold! Don’t start exercising again too soon either! The increased strain in combination with the viral infection can lead to inflammation of the heart muscle (myocarditis) or the pericardium (pericarditis). Both can lead to irreparable heart damage such as heart failure (cardiac insufficiency) and can even be life-threatening.
You can find more detailed information on exercising when you have a cold in the article “Exercising when you have a cold”.
Colds: prevention
Do you want to prevent a cold? Then you should make sure you eat a balanced and varied diet. This will provide your body with all the important nutrients (such as vitamins and minerals) that it needs for a strong immune system, among other things.
It is also good for your immune system if you avoid stress and regularly relax in your everyday life.
Other tips to help you keep a cold at bay, especially in summer, include
- Make sure you don’t get cold when swimming in an outdoor pool, sea or lake.
- When swimming, take a break if you get cold and dry yourself well.
- Change damp or sweaty clothes as quickly as possible.
- If possible, avoid air conditioning (car, restaurant, etc.) and draughts.
- Drink plenty of water. Fluid also keeps the mucous membranes moist, which is the only way they can fulfill their function as a natural protective shield against pathogens (such as a cold).
You can find out more about this topic in the article “Preventing colds”.