COVID-19, cold, flu: the symptoms at a glance

COVID-19, common colds and flu are all infectious respiratory conditions caused by infection with a specific pathogen. The infections are caused by a number of different viruses. Whereas rhinoviruses can be responsible for common colds and influenza viruses for flu, for example, COVID-19 is caused by the SARS-CoV-2 coronavirus. 

As the symptoms of COVID-19 are similar to those of flu or the common cold, the conditions cannot be distinguished by the symptoms alone. Even a self/rapid test – unlike a laboratory test – cannot necessarily do this.

Further information on what people should do in the event of a suspected SARS-CoV-2 infection and when quarantine and isolation are necessary can be found at infektionsschutz.de – a website from the Federal Center for Health Education (Bundeszentrale für gesundheitliche Aufklärung – BZgA).

For many people with COVID-19 in Germany, the symptoms are a cough, high temperature or rhinitis (sneezing, itchiness and a blocked or runny nose). Other potential symptoms are a sore throat, headaches and joint pain as well as general debility and, in the more advanced stages, dyspnea (shortness of breath). One distinct feature of COVID-19 is that people can experience changes to their sense of smell or taste.

They may also experience nausea, abdominal pain, diarrhea, conjunctivitis, a skin rash, lymphedema and light-headedness. 

There are many different forms that COVID-19 can take and they vary considerably. Infection with the SARS-CoV-2 coronavirus can be asymptomatic. However, there are also severe cases with complications such as pneumonia, which can lead to lung and organ failure or even death. 

A characteristic sign of flu (influenza) is the sudden onset of the condition with a high temperature, cough and sore throat accompanied by headache and/or joint pain and in most cases severe discomfort.

Other possible symptoms include general debility, severe sweating, rhinitis (sneezing, itchiness and a blocked or runny nose) as well as in rare cases nausea, vomiting and diarrhea.

Only a third of people infected with flu have the typical form of the condition with a high temperature. Another third have a milder form and the final third do not develop any symptoms at all.

Most forms of flu are mild and people recover within a week without the need for treatment. However, the cough and general feeling of weakness can persist for much longer.

The most common complications of flu involve pneumonia. Middle ear infections may also develop in children. Encephalitis or myocardial inflammation are rare.

What happens during a flu outbreak?

Almost everyone contracts flu as a child and develops a basic level of immunity at an early age. Since flu viruses mutate very rapidly though, many people become susceptible to the flu again within a few years of an infection.

During a flu outbreak approximately 5% to 20% of the population is infected. There can also be “peaks” where a particularly high number of people become infected and ill.

Particularly severe flu outbreaks where lots of people need to be treated and ventilated in intensive care units at the same time can temporarily and regionally overload the healthcare system.

Increasing numbers of infections and simultaneous outbreaks of COVID-19 and flu risk exacerbating the care situation in hospitals and intensive care units.

Further information about the flu can be found at www.infektionsschutz.de (in German).

The GrippeWeb – an online portal from the Robert Koch Institute – also provides additional information about the flu (in German).

A common cold is often characterized by rhinitis (sneezing, itchiness and a blocked or runny nose), coughing and occasionally a sore throat. High temperatures are less common in colds than in flu. Complications do not usually occur.

Further information about the common cold can be obtained from the Lung Information Service provided by the Helmholtz Zentrum München.

The best way to protect yourself and others from an infection with cold, flu and SARS-CoV-2 viruses is to avoid close contact with other people and follow the hands, face, space (AHA) and ventilation (+L) guidance.

A further important measure with regard to infection control is to get vaccinated against COVID-19 and the flu. Where necessary, doctors can administer these vaccinations at the same time.

Further information about COVID-19 and vaccination can be found in the article COVID-19 vaccination: answers to the most important questions. 

The website www.impfen-info.de provides questions and answers on the topic of flu vaccination (in German).

Information on how to properly follow the hands, face, space, ventilation (“AHA+L”) guidance and what to bear in mind can be found at www.infektionsschutz.de (in German).