COVID-19 can cause various different symptoms. The illness is different in different people. In many cases, infected people have only mild symptoms or no symptoms at all.

Frequent symptoms:

• cough
• runny nose
• fever with a temperature above 38^o C
• hoarseness, sore throat
• headache and aching limbs
• impaired senses of taste and smell
• breathlessness, respiratory distress

After the acute illness, some people experience further symptoms such as exhaustion (fatigue), nausea, concentration problems, dizziness, and other neurological symptoms. This is known as post-COVID-19 syndrome or long COVID.

A summary of COVID-19 symptoms and a wealth of additional information is available from the Robert Koch Institute (RKI).

Information about COVID-19 is available in different languages from the World Health Organization (WHO) and in English from Pfizer Inc.

COVID-19 and the flu are both infectious diseases of the airways and they cause similar symptoms: coughing, sneezing, runny nose, fever, headache and aching limbs.

They are caused by different pathogens. Flu is caused by influenza viruses and COVID-19 is caused by the SARS-CoV-2 virus.

How the illness develops is dependent on many factors such as age, state of health and pre-existing conditions. In the case of COVID-19, the different waves of the pandemic have shown that the risk of serious illness is also dependent on the virus variant.

If you experience the symptoms we have just described, you should stay at home, avoid contact with other people and call a doctor to ask for advice. You can find out whether you have COVID-19 by taking a test.

Further information comparing COVID-19 and flu is available at the Federal Health Ministry’s health website gesund.bund.de.

Information in different languages on the comparison between COVID-19 and flu is available from the World Health Organization (WHO).

No, COVID-19 is not a hereditary disease.

However, it is not impossible that a pregnant woman could pass on the illness to her unborn child. Individual cases of the illness have been reported in new-born babies who may have become infected before birth.

The risk of infection is greater after birth. Because of the close contact between mother and child, the virus can be transmitted from the mother to her new-born baby in airborne droplets or aerosols.

To reduce the risk for new-born babies, STIKO, Germany’s Standing Committee on Vaccination, therefore recommends that pregnant and breast-feeding women be vaccinated against COVID-19.

Pregnant women are recommended to have the vaccination during the second trimester of pregnancy. Women who received the first vaccination before they became pregnant should have their second vaccination in the second trimester of pregnancy.

Further information is available at the Federal Health Ministry’s website infektionsschutz.de.

The infection is mainly passed on through virus-containing droplets and aerosols in the air we breathe.

When we breathe, speak, sing, shout, sneeze and cough we emit tiny droplets and aerosols which can remain in the air for a long time. Just how long depends on the size of the droplets. Droplets spread over a radius of 1.5 to 2 meters while aerosols can spread much further. The droplets and aerosols emitted by infected people contain small amounts of the virus. If someone else breathes them in, the virus gets into their body where it can reproduce.

Infections occur mainly in badly-ventilated indoor spaces and when an infected person is nearby.

The virus can also be transmitted on our hands or via contaminated surfaces (fomite transmission) but this route is less important than airborne transmission for the overall spread.

Read our section on “Everyday prevention” to find out how you can protect yourself from becoming infected.

Further information about the different transmission routes is available from the Federal Health Ministry’s website infektionsschutz.de.

One problem is that patients who have mild COVID-19 at home often do not notice when their illness turns into sepsis.

Sepsis is always an emergency. This means it's important to recognize the symptoms of sepsis early on.

If someone with COVID-19 suddenly feels very ill and has chills, fever, a fast pulse rate and confusion, they should go straight to hospital or call the emergency service.

Further information about sepsis is available from Deutschland erkennt Sepsis, an initiative of the patient safety alliance APS.

A number of factors can increase the risk of severe illness with COVID-19. This means that certain groups within society are at greater risk and are therefore referred to as “high-risk groups” or “vulnerable groups”.

The most important risk factors are:

• Age

Above 60 years, the risk of severe illness increases progressively with increasing age.

• Pre-existing conditions

Diabetes, lung, liver, kidney and cardiovascular diseases, cancer, organ transplantation and severe mental illness can all increase the risk of severe illness. Many disabled people are also at increased risk, for example because paraplegia can limit lung function.

• Being very overweight (obesity)

People who are obese (with BMI over 30) and contract COVID-19 are twice as likely to be admitted to hospital. Studies have shown that fat cells can have a negative effect on the course taken by the illness.

• Immunodeficiency

People whose immune systems are compromised because of illness or medical treatment are at increased risk.

• Smoking

Because of the damage often caused to their lungs, smokers are at increased risk of severe illness.

Risk factors can reinforce each other. So when someone has several different risk factors together, as is the case for older or overweight people who also have other pre-existing conditions, it is especially important that they take care to avoid infection.

Further information about high-risk groups and risk factors is available at the Federal Health Ministry’s website Zusammen gegen Corona and from the Robert Koch Institute (RKI).

COVID-19 occurs in all age groups. However, there are differences with regard to its frequency and severity.

Most of the COVID-19 cases in Germany so far have been in the 35 to 59–year-old age group with 15- to 34-year-olds in second place.

The risk of dying from COVID-19 increases with age. People aged over 80 years are at the greatest risk, followed by people aged 60 to 79 years.

In children, the illness is more often mild or asymptomatic (which means it has no symptoms at all). In older people, mild illness is less common. Importantly, even when the illness is mild, clear symptoms can occur.

Further information about the spread of the illness in Germany is available from the COVID-19 Dashboard of the Robert Koch Institute (RKI).

International data about the spread is available from the Coronavirus dashboard of the World Health Organization (WHO).

At the time of writing (April 2022), more than 500 million people throughout the world, 24 million of them in Germany alone, have caught COVID-19 since the start of the pandemic at the end of 2019.

Women and men become infected with the SARS-CoV-2 coronavirus in about equal measure. However, the illness often takes a more serious course in men. The proportion of men who die from COVID-19 is about twice as high as the proportion of women.

Current case numbers for Germany are available from the Robert Koch Institute (RKI) and for the whole world from the World Health Organization (WHO).

SARS-COV-2 is a pathogenic virus belonging to the coronavirus family. It takes its name from the crown-like spikes on the virus envelope, “corona” being the Latin word for crown.

At present, we know of seven different coronaviruses that can infect humans. Four of them mainly cause mild cold symptoms or diarrhea while the other three are more dangerous and can cause severe airway infections:

• SARS-CoV

The SARS-CoV coronavirus (which is also called SARS-CoV-1) causes Severe Acute Respiratory Syndrome or SARS. There was an outbreak in 2002-2003, occurring mainly in China but affecting some other countries as well. Around the world, about 8000 people became infected and about 800 of them died from the effects of the illness. Further information about SARS is available from the European Center for Disease Prevention and Control.

• MERS-CoV

The Middle East Respiratory Syndrome Coronavirus (MERS-CoV) can cause severe airway infections, pneumonia and kidney failure. MERS-CoV was first detected in 2012. Up to now, most cases of MERS have occurred on the Arabian Peninsula in the Middle East. It is thought that many people become infected as a result of contact with infected dromedaries. In other parts of the world such as Africa, Asia and Europe, only a few imported cases have so far been detected. Further information is available from the Robert Koch Institute (RKI).

• SARS-CoV-2

SARS-CoV-2 is the pathogen causing COVID-19. Up to now, it is the most dangerous member of the coronavirus family as far as humans are concerned. A number of different variants of the virus have arisen as a result of mutations (changes) in the virus’s genetic make-up. These have been named with letters of the Greek alphabet (alpha, beta, gamma, delta, omicron). Such variants are considered to be a cause for concern if, for example, they are particularly infectious or if they are particularly likely to cause serious illness.

You’ll find more information about COVID-19 and SARS-CoV-2 in our other sections.

Information about COVID-19 is available in different languages from the World Health Organization (WHO) and in English from Pfizer Inc.

COVID-19 is an infectious disease caused by a virus called SARS-CoV-2 which primarily strikes the airways but can also affect other organs.

The first cases occurred in Wuhan, China, at the end of 2019. A little later the virus spread to other countries and caused a worldwide pandemic.

The name COVID is an abbreviation of “coronavirus disease”. The number 19 stands for the year 2019 when it all began.

More information is available on infektionsschutz.de, the website of the Federal Centre for Health Education (BZgA), on the Health Ministry’s websites Zusammen gegen Corona and gesund.bund.de and from the Robert Koch Institute (RKI).

Information about COVID-19 is available in various languages from the World Health Organization (WHO) and in English from Pfizer Inc.