Long COVID – long-term effects of COVID-19

As can happen with other infectious diseases, people who contract COVID-19 sometimes experience health problems for weeks or even months after recovering from the initial SARS-CoV-2 infection.

If the symptoms persist for more than 4 weeks after the acute infection or if new symptoms develop that cannot be explained in any other way, this is known as long COVID. If symptoms last for more than 12 weeks, this is known as post COVID-19 condition or post COVID for short.

Anyone who suffers from a severe case of COVID-19 is at a higher risk of developing long COVID. However, long-term consequences are also possible following mild cases and infections without symptoms.

Long-COVID can affect both adults and children following a coronavirus infection.

People with long COVID report a wide range of physical and psychological symptoms. These can be so severe that they reduce people’s quality of life, make their everyday life difficult and impair their working and social life.

To alleviate the symptoms as far as possible and improve the quality of life and physical capacity of people with long-term effects of COVID-19, early and targeted advice and treatment are essential.

The symptoms described by people with long COVID differ greatly. Many people experience several symptoms at the same time.

The most common symptoms are tiredness and rapid exhaustion – also known as fatigue.

People with long COVID often also complain of having reduced stamina and being short of breath. Many also have a limited ability to concentrate and impaired memory – this is commonly known as brain fog.

Furthermore, the following symptoms may occur after the acute SARS-CoV-2 infection has passed:

• muscle weakness and muscle pain
• lost or changed sense of smell and taste
• persistent cough
• sleep disorders and non-restful sleep
• psychological stress, such as depression and anxiety
• increased hair loss
• chest pain and perceived heart palpitations or skipped heartbeats
• cardiovascular diseases, such as high blood pressure
• gastrointestinal problems

Some people find that their lung, liver, kidney or heart functions are impaired. For example, they may develop myocarditis (inflammation of the heart muscle), diabetes or thromboembolisms – where blood clots cut off the blood supply.

Long COVID occurs as a result of infection with the coronavirus SARS-CoV-2, the COVID-19 pathogen.

What exactly causes long COVID is not yet fully known. Experts assume that various factors play a role. These factors can work in combination or in isolation.

Firstly, it is assumed that inflammatory processes that primarily affect the blood vessels and thus various organ systems continue to occur in the body after a coronavirus infection.

Autoimmune responses – where the body attacks its own cells – may also play a role in the development of long COVID.

Secondly, there are indications that changes to the blood cells, functional disorders of the vascular, nervous and immune systems and the blockage of usually tiny blood vessels by blood clots (microthromboembolisms) can play a role in the condition’s development.

The information available on the prevalence of long COVID differs greatly from one study to the next.

It depends, for example, on:

• the type and size of the sample group
• the length of the observation period
• the number and type of symptoms and health impairments recorded

Available data indicates that approximately 8% to 41% of adults and 2% to 4% of children who were treated in hospital still have one or more symptoms long after they have recovered from an acute SARS-CoV-2 infection. Among those who required hospital treatment, the figures are around 38% of adults and 25% of children.

Based on what is currently known, women appear to be more likely than men to develop long COVID. Children and adolescents seem to be less likely than adults to suffer from long COVID. However, this has yet to be conclusively clarified.

Research has yet to conclusively determine exactly which factors increase the risk of developing long COVID.

The latest findings indicate that people who suffer a severe initial infection with COVID-19 are more likely to suffer long-term consequences.

In addition, the likelihood of suffering long-term consequences of COVID-19 appears to be higher among people with pre-existing psychological and physical conditions, such as asthma, and among people who are severely overweight (obese).

Factors such as age and gender also influence the development of long COVID.

Risk factors that have been identified to date include:

• a high viral load at start of the infection
• the presence of autoantibodies – these are produced by a faulty immune response and target the body’s own tissue
• reactivation of the Epstein-Barr virus – this virus remains in the body following an infection and can be reactivated when the immune system is weakened

To date, long-term studies of patients with long COVID have been limited. 

However, it is important to know the circumstances under which symptoms recur or remain and the extent to which severe organ complications occur.

Identifying these factors is essential to helping people with long COVID at an early stage and in a targeted way.

To date, the only known way to avoid developing long COVID is to avoid becoming infected with the SARS-CoV-2 coronavirus.

In addition to observing the public health guidance on washing hands, wearing a mask on an everyday basis and keeping indoor areas well ventilated, vaccination against COVID-19 offers another way to prevent infection.

Several studies indicate that full immunization can reduce the frequency and extent of long COVID symptoms. Vaccination may also have a positive effect in people who have already recovered from a SARS-CoV-2 infection and are showing symptoms of long COVID. However, this has not yet been proven.

Experts have developed initial recommendations for diagnosing long COVID. These recommendations will be developed on an ongoing basis to improve medical care.

However, it is difficult to diagnose long COVID because it is not yet possible to clearly distinguish between the symptoms of long COVID and those of other conditions. In addition, it is not always possible to establish a definite link with a prior SARS-CoV-2 infection – for example, because people may have an infection without experiencing any symptoms or because an infection was not established by means of a test. 

If it is known that the person has previously had a COVID-19 infection, doctors will ask which symptoms occurred during the acute phase of the illness and which are currently persisting.

They will also ask whether and what new health issues have developed and whether any symptoms that were already present prior to the infection have worsened as a result of the illness.

The aim is to record all physical and psychological symptoms, as well as any limitations these have caused.

The doctor may ask the following during the consultation:

• whether and to what extent everyday life and work are negatively affected
• whether the person feels socially isolated
• whether the person has any psychological symptoms, such as anxiety, or is showing signs of depression
• whether and to what extent the person’s mental and physical capabilities are limited

Depending on the type and severity of the symptoms or if the person is experiencing non-specific problems, they may need to be referred to a specialist.

There is, as yet, no specific treatment for long COVID. Teams of doctors and researchers are working hard to develop suitable treatment concepts.

To optimally alleviate the symptoms and improve the quality of life and physical capacity of people with long COVID, early and targeted medical advice and treatment options are important.

These are tailored to the patient’s individual clinical picture and life situation. A key aim is to prevent the symptoms from becoming chronic.

Depending on the type and strength of the physical or mental impairments, various measures help to improve patients’ health. These include:

• pain therapy
• physical and mental (cognitive) training
• guidance on sleep hygiene
• techniques to reduce stress
• psychotherapeutic care

Depending on which organ systems are affected, specialist medical treatment may also be necessary.

It is also essential for people with long COVID to learn to deal with their illness better during their daily lives. Personalized guidance from trained personnel can help them do this.

Rehabilitation by a trained, interdisciplinary team can help people with long COVID regain their physical and mental strength and resilience.

Rehab can occur in an inpatient or outpatient capacity. Depending on the severity of the limitations, it is also possible to obtain aftercare and services that help people with their working life.

Further information about rehabilitation for long COVID can be found on the websites of the German pension insurance organization (“Deutsche Rentenversicherung”) and the Federal Ministry for Labor and Social Affairs (“Bundesministerium für Arbeit und Soziales”).

In some situations, statutory accident insurance providers will recognize COVID-19 as an occupational disease or work accident. People for whom that applies can contact their insurance provider if they want to receive rehabilitation services due to long COVID.

Self-help groups offer people with long COVID and their loved ones a way of obtaining information and advice, and of sharing personal experiences.

Further information about COVID-19 self-help groups can be found on the website of the National Contact and Information Point for Encouraging and Supporting Self-Help Groups (Nationale Kontakt- und Informationsstelle zur Anregung und Unterstützung von Selbsthilfegruppen – NAKOS).

In addition, clinics and hospitals offer long COVID consultations or run long COVID outpatient clinics, which people can attend to obtain advice.

An overview of post COVID-19 clinics in Germany is provided on the website of the Long COVID Initiative Germany (“Initiative Long COVID Deutschland”).

For more information about the long-term effects of a coronavirus infection, see the websites of the Federal Center for Health Education (“Bundeszentrale für gesundheitliche Aufklärung”, BZgA) and the Robert Koch Institute (RKI).