Colds (flu-like infections): What really helps?

How common are colds, and what causes them?

Colds are very common. Adults catch a cold on average two to five times a year, whilst children catch one six to ten times a year. Colds are particularly common during the colder months and when there are significant fluctuations in temperature. A cold is caused by viruses. There are over 200 different viruses known to cause a cold-like infection. Among the most common are:

• rhinoviruses
• Coronaviruses
• Parainfluenza viruses
• Adenoviruses
• Respiratory syncytial viruses

Unlike genuine flu (influenza), which is caused by influenza viruses, there is no vaccine against most common cold viruses. However, vaccines are available for specific pathogens such as RSV and COVID-19.

How do you catch a cold-like infection?

The viruses are usually transmitted through the air – for example, through close contact with people who have a cold. When someone sneezes or coughs, viruses can be spread several metres, but pathogens are also present in normal exhaled air. Infection is also possible if the viruses are transferred to the mucous membranes of the nose and mouth via your own fingers. That is why it is important to wash your hands frequently and thoroughly, for example after shopping, using other people’s keyboards or travelling on public transport. Viruses and bacteria can also survive on mobile phones and tablets for several days. The following factors can weaken the immune system and thus increase the risk of catching a cold:

• not getting enough sleep
• stress
• an unbalanced diet low in vitamins
• inappropriate clothing in cold weather

Exposure to the cold, particularly around the nose and ears, can also irritate the mucous membranes and make you more susceptible to infection.

What are the symptoms of a cold?

A cold often improves after a few days, but usually clears up within about seven to ten days. Nevertheless, the symptoms can be very unpleasant and significantly disrupt daily life. Typical symptoms of a cold are:

• a blocked or runny nose
• sore throat (inflamed throat)
• cough
• hoarseness

With a viral infection, the nasal discharge is usually clear. If it is yellow-greenish and very thick, this may indicate a bacterial infection. This often develops later on, once the mucous membranes have already been weakened. This is referred to as a ‘bacterial superinfection’. The infection is usually confined to the upper respiratory tract. However, in severe cases, the viruses or bacteria may spread. Possible symptoms include:

• Fever
• Aches and pains
• Headache
• severe sore throat (pharyngitis)
• Bronchitis
• Sinusitis
• Middle ear infection (particularly in young children)

How long is a cold contagious?

When a cold becomes contagious and for how long can vary. In principle, it is possible to pass the infection on to others even before symptoms appear. However, the greatest risk of transmission is usually two to three days after the first symptoms appear. As long as the person with the cold is showing symptoms, the illness can still be passed on, for example through contact or droplet transmission. How long a person is actually contagious also depends on the specific pathogen and the state of their immune system. A study from Yale in 2026 showed that the immune system’s response is crucial to the course of a cold, particularly in the case of rhinoviruses. The more effectively the cells in the nose combat the pathogen, the milder the subsequent cold symptoms will be. Two people who have been infected with the same pathogen may therefore react to it with varying degrees of severity.

What is the difference between a common cold and the real flu?

A common cold and the real flu (influenza) can cause similar symptoms and are therefore not always easy to distinguish from one another. Nevertheless, there are typical differences in how they progress:

Common cold

• begins gradually with a scratchy throat, a sore throat or a runny nose
• A runny nose is very common
• Fever is rare and is usually mild
• usually lasts 7 to 10 days

Flu (influenza)

• begins suddenly with a high fever (38–40 °C), chills, headache and aching limbs
• often accompanied by a dry cough; a runny nose is rather rare
• usually lasts up to two weeks; this is followed by a longer recovery period during which you feel weak

Both the symptoms of a common cold and those of genuine flu can resemble the symptoms of COVID-19. If in doubt, a test for SARS-CoV-2 infection should be carried out. You can read more about the difference between flu, the common cold and COVID-19 here.

What helps with a cold?

There is no specific medication to treat a common cold. Treatment therefore focuses primarily on relieving symptoms and helping the body to recover.

Rest and sleep

One of the most important factors is getting plenty of rest. If you take it easy whilst you have a cold, you will usually recover more quickly. Strenuous physical activity, such as intense exercise, can delay recovery and, in rare cases, lead to complications.

Staying well-hydrated

Drinking plenty of fluids helps to keep the mucous membranes moist and loosen phlegm. Water, herbal teas or clear soups are recommended. Chicken soup, in particular, has proven to be very effective. It has been shown to have anti-inflammatory properties and promotes a sense of well-being.

Home remedies for relief

Many traditional home remedies have stood the test of time and can help to alleviate cold symptoms naturally. Chamomile tea has anti-inflammatory and soothing properties; ginger warms the body from within and stimulates blood circulation; and sage tea can be particularly soothing for a sore throat and hoarseness. Honey is excellent for soothing a tickly cough and caring for irritated mucous membranes – however, it is not suitable for children under one year of age. Inhalations using steam or saline solution moisturise the airways and make breathing easier. Read more about home remedies for a cold here. Find out how to treat a cough with home remedies here.

Medication as required

Active ingredients such as paracetamol or ibuprofen can be used to relieve pain and reduce a fever. They do not treat the cause of the cold, but they do provide noticeable relief from the symptoms. Decongestant nasal sprays provide relief from a blocked nose, but should not be used for longer than a few days. Cough medicines may be useful, depending on the type of cough. It is important to tailor their use to your symptoms and to follow the recommended dosage.

Indoor climate

Dry air from central heating can put additional strain on the mucous membranes. Regular ventilation and sufficient humidity in the room aid recovery – particularly in children. You can read more about treating colds here.

How does a flu-like infection progress in children?

Children catch colds particularly frequently. This is because their immune system is not yet fully developed and still has to learn how to cope with the many different viruses. It is therefore normal for them to have several infections a year. Colds in children are usually uncomplicated and clear up on their own. Strict bed rest is generally not necessary. A calm daily routine is more important to ensure the child can recover properly. The following measures can aid recovery:

• plenty of rest and sleep
• adequate fluid intake: children should drink enough to help loosen the mucus.
• adequate humidity in the room
• use only home remedies that are suitable for children

When should you take a child with a cold to see a doctor?