At a glance

  • The typical symptoms of a cold are a cough, a stuffy nose and a sore throat.

  • Colds are caused by a harmless viral infection.

  • The symptoms normally go away on their own within a week.

  • You usually don't need to take any medicine.

  • Washing your hands and keeping your distance from others can protect you from getting a cold.

Introduction

Photo of someone washing their hands (PantherMedia / subbotina)

Common colds, or simply “colds,” are usually quite harmless and go away again on their own. The symptoms of a cold such as a cough, sore throat and a runny nose can be really annoying. A severe cold can make you feel weak and ill, too.

Colds usually go away on their own after about a week, but some symptoms may last longer. Although a sore throat or a stuffy nose may be gone after just a few days, it can sometimes take up to three weeks for a cough to disappear completely.

Treatment with medication usually isn’t necessary. Some medications may, at best, help relieve the symptoms a bit. Because colds are typically caused by viruses, it also doesn't make sense to use antibiotics to treat an ordinary cold. Antibiotics only fight bacteria.

Symptoms

Colds usually take a few days to fully develop. Typical symptoms include a stuffy or runny nose, sneezing, coughing and a sore throat. Sometimes a cold is also accompanied by a mild fever, weakness, a headache and joint pain.

Occasionally, colds are mistaken for the flu. But flu symptoms are usually much worse. Also, a flu doesn't develop gradually. Instead, it generally starts very suddenly with a high fever, chills, and aching muscles and joints.

Causes

Colds can be caused by various viruses. They lead to inflammations in the lining of the nose and throat, but are otherwise harmless.

This makes them different from true flu viruses or the new coronavirus (SARS-CoV-2), for instance. An infection with these viruses can also cause cold-like symptoms, and they may be mild. But it can also result in a severe infection of the airways, like pneumonia.

Prevalence

Colds are very common, especially in children. It's quite normal for children to catch 6 to 10 colds per year – at school, daycare or kindergarten. Adults have 2 to 4 colds a year on average, mostly during the colder time of year.

Outlook

Colds often start with a sore throat, usually soon followed by a runny or stuffy nose. Even though you might feel quite ill during a cold, it usually doesn't cause any harm. Your immune system can fight off the infection without any problems.

The worst is typically over within a week. But it can take a little longer for the symptoms to go away completely. Coughs in particular can be stubborn. Adults need 18 days on average to completely recover from a cough, and it can take up to three weeks in children too.

Effects

Colds are usually harmless and clear up without any serious consequences. But bacteria can sometimes spread through the airways after a viral infection, and they may cause more severe problems in various places, such as in the sinuses.

If the larynx (voice box) is inflamed, your voice becomes hoarse. Young children may develop croup too. Croup is caused by viruses. The typical symptoms are a "barking" cough, raspy sounds when you breathe in and mild breathing difficulties.

In babies, infants and toddlers, colds sometimes spread to the ear and lead to a middle ear infection. Bacterial infections in the throat can cause tonsillitis.

Infections of the upper airways (in the nose, mouth and throat area) only very rarely cause serious complications like pneumonia. It's a good idea to see a doctor if you have a high fever, severe or worsening symptoms, chest pain, shortness of breath or trouble breathing. This is especially important for people who have a chronic disease of the airways, such as chronic obstructive pulmonary disease (COPD).

 Illustration: AirwaysAirways

Diagnosis

No special tests are needed for doctors to diagnose a cold. Because practically everyone knows the symptoms from childhood, most people don't go to see the doctor. Doctors usually just need to look into your throat and ask you what symptoms you have.

Colds are very common, so it's much less likely that you have another illness with similar symptoms. But if your doctor thinks you may have the flu or another more serious infection, tests like nose or throat swabs can help to find out.

Prevention

Because there are so many different cold viruses, having recovered from a cold doesn't stop you from catching another one. Your immune system needs to learn how to fight each new virus. This also means that it's not possible to vaccinate against colds.

But there are some simple things you can do to avoid catching a cold, like keeping your distance from others and washing your hands. The viruses spread through droplets: When someone with a cold sneezes or coughs, a lot of tiny virus-containing drops are sprayed into the air, and they come to rest on objects like doorknobs, computer keyboards or handles and poles on the subway. If you touch these objects, the viruses may get on to your hands. Touching your face with your hands could then easily spread the viruses to your nose or mouth. So avoiding touching your face with your hands is one way to reduce your risk of catching a cold. It's also important to wash your hands often with regular soap.

If you are already ill and have to sneeze and cough a lot, it's best to keep your distance from other people. That also means that you shouldn't go to work if you have the symptoms of a cold.

Cold viruses are spread through objects that have touched the nose or mouth of a person with a cold. This includes cups or glasses that the person might have used to drink out of, and of course used tissues as well. So it’s important to throw tissues away immediately after use, and avoid leaving them lying around.

Vitamins or echinacea products are sometimes recommended for the prevention of colds. Some people already start taking these kinds of products a few weeks before the cold season starts. But they offer very limited protection.

Research summaries

Treatment

Because there are so many different cold viruses, there is currently no medicine that can fight cold viruses and noticeably shorten the length of colds. But various medications can relieve some of the symptoms a little. These include painkillers like ibuprofen and acetaminophen (paracetamol), as well as decongestant (anti-swelling) nasal sprays for temporary use.

Antibiotics are not effective against cold viruses and should only be used if bacteria are also involved and complications have developed. The antibiotics often have side effects too.

Products that contain zinc, vitamin C, or echinacea extracts are also commonly recommended for the treatment of colds. It's not currently possible to reliably assess the advantages and disadvantages of these products because there has either been too little research or the studies that have been done have produced contradictory results.

Honey or herbal products like extracts taken from Pelargonium (umckaloabo), primrose, thyme, eucalyptus and ivy leaves may possibly relieve a cough somewhat.

Learn more

Further information

When people are ill or need medical advice, they usually go to see their family doctor first. Read about how to find the right doctor, how to prepare for the appointment and what to remember.