Post-acute COVID-19 Syndrome

Post-acute COVID-19 syndrome is a condition where symptoms continue or develop weeks, months, or even years after recovering from the initial COVID-19 infection, affecting multiple organs and significantly impacting daily life.

long COVID, long-haul COVID, post-COVID-19 syndrome, post-acute sequelae of SARS-CoV-2 (PASC), post-COVID conditions (PCC), chronic COVID

Table of contents

• What is Post-acute COVID-19 Syndrome?
• Symptoms and Their Impact
• Who Can Develop This Condition?
• Possible Causes
• Diagnosis and Testing
• Treatment and Management
• Prevention
• Living with Post-acute COVID-19 Syndrome

What is Post-acute COVID-19 Syndrome?

Post-acute COVID-19 syndrome refers to a collection of symptoms and health problems that continue or appear after the acute phase of COVID-19 infection has ended. While most people recover from COVID-19 within a few weeks, a significant number experience ongoing or new symptoms that can last for months or even years^[1].

The condition is defined as a chronic condition (meaning long-lasting) that occurs after SARS-CoV-2 infection and is present for at least three months^[3]. Some experts define it as symptoms lasting four weeks or longer after the initial COVID-19 illness^[2]. The World Health Organization describes it as occurring in individuals with a history of probable or confirmed SARS-CoV-2 infection, usually three months from the onset, with symptoms that last for at least two months and cannot be explained by another diagnosis^[9].

This condition is recognized as a serious illness that can result in chronic conditions requiring comprehensive care and may even cause disability^[3]. The symptoms can be similar to those of autoimmune (when the body’s defense system attacks itself), lung, heart, brain, or psychological disorders^[6].

Symptoms and Their Impact

Post-acute COVID-19 syndrome can affect multiple organ systems throughout the body. Research studies have linked more than 200 different symptoms to this condition^[2]. The symptoms may stay the same over time, get worse, or go away and come back^[2].

The two most common symptoms are extreme tiredness and shortness of breath^[2]. Other frequently reported symptoms include:

• Extreme fatigue, especially after physical activity
• Problems with memory and concentration, often called “brain fog” (difficulty thinking clearly)
• Loss of or altered sense of smell or taste
• Sleep problems or insomnia (inability to sleep)
• Shortness of breath
• Chronic cough
• Headaches and body aches
• Feeling lightheaded or dizzy
• Fast or irregular heartbeat (palpitations)
• Chest pain
• Depression and anxiety
• Digestion problems such as diarrhea, constipation, or bloating^[2][6]

Some people with post-acute COVID-19 syndrome may develop other illnesses or have existing conditions worsen. Diseases that may be diagnosed due to this condition include heart disease, mood disorders, stroke or blood clots, and a condition called postural orthostatic tachycardia syndrome (POTS), where the heart rate increases abnormally when standing up^[2]. Other conditions include migraine, lung disease, autoimmune disease, and chronic kidney disease^[2].

About one in five adults with this condition have reported experiencing significant limitations in their daily activities^[17]. Some people find that symptoms prevent them from returning to work or school, while others have difficulties performing everyday chores or even walking short distances^[6][15].

Who Can Develop This Condition?

Anyone who has had a SARS-CoV-2 infection can experience post-acute COVID-19 syndrome, including children^[3]. The condition can develop whether someone had a mild, moderate, or severe case of COVID-19. It can even occur in people who had no symptoms during their initial infection^[15].

Post-acute COVID-19 syndrome may affect about 5% to 10% of people who have had a COVID infection^[6]. Some studies have found higher rates, with estimates suggesting it occurs in 5% to 30% of people with COVID-19^[15].

While anyone can develop this condition, certain groups of people are more likely to experience it:

• Women
• Hispanic and Latino people
• People who experienced more severe COVID-19 illness, especially those who were hospitalized or needed intensive care
• People with underlying health conditions such as diabetes, asthma, or obesity
• Adults who are 65 or older
• People who did not get a COVID-19 vaccine^[3][15]

People can be reinfected with SARS-CoV-2 multiple times. Each time a person is infected, they have a risk of developing post-acute COVID-19 syndrome^[3]. Health inequalities from disability, economic, geographic, and other social factors can increase the risk of negative health outcomes from this condition^[3].

Possible Causes

The exact causes of post-acute COVID-19 syndrome are not yet fully understood. Other coronaviruses, including Middle East respiratory syndrome (MERS) and severe acute respiratory syndrome (SARS), have been known to cause long-term effects, so it is not surprising that COVID-19 symptoms can last a long time^[6].

Researchers have proposed several theories about what might cause this condition:

Tiny blood clots: Very small blood clots might not cause a major event like a stroke, but they can prevent the lungs, brain, and other organs from working properly^[6].

Inflammation: The immune system may overreact and continue to cause inflammation (swelling and irritation) in organs and tissues long after it has fought off the infection^[6].

Autoimmune disorders: For reasons not fully understood, COVID-19 might cause the immune system to start attacking parts of the body itself, similar to an autoimmune disorder^[6].

Viral persistence: SARS-CoV-2, the virus that causes COVID-19, might remain in the body long after a person feels better from their initial illness. A person can test negative for COVID-19 and not be contagious anymore, but the virus could continue to cause issues in the body^[6][15].

Reactivation of other viruses: Some viruses remain inactive in the body without causing symptoms. These can sometimes get reactivated and cause symptoms again. Some evidence suggests that COVID-19 might reactivate Epstein-Barr virus, which causes mononucleosis (an infectious disease)^[6][15].

Cellular damage, a robust immune response with inflammatory substances, and a pro-coagulant state (increased tendency for blood to clot) induced by SARS-CoV-2 infection may contribute to these long-term effects^[1].

Diagnosis and Testing

Post-acute COVID-19 syndrome is not one single illness. There is no specific laboratory test that can determine if symptoms or conditions are due to this syndrome^[3]. A positive SARS-CoV-2 test is not required for diagnosis^[3].

Healthcare providers consider a diagnosis of post-acute COVID-19 syndrome based on a person’s health history, whether they had a diagnosis of COVID-19 by a positive test, symptoms, or exposure to the virus^[3]. The diagnosis is made when symptoms cannot be explained by another medical condition and occur in someone with a history of COVID-19 infection.

Most people with this syndrome experience symptoms days after first learning they had COVID-19, but some people who later develop the condition do not know when they were infected^[3]. Because symptoms can affect multiple organ systems, evaluation may require specialists from different medical fields working together.

Treatment and Management

Because post-acute COVID-19 syndrome has different symptoms and possible causes, there is no single treatment that works for everyone^[6]. Treatment depends on the specific symptoms a person is experiencing and is tailored to each individual case^[9].

Management of chronic health conditions and other existing diseases is essential throughout treatment^[9]. A multidisciplinary approach (care from specialists in different areas) is often recommended. This may include specialists from fields such as:

• General internal medicine or family medicine
• Infectious diseases
• Pulmonary medicine (lungs)
• Cardiology (heart)
• Neurology (brain and nerves)
• Psychiatry and psychology (mental health)
• Rehabilitation medicine (occupational, physical, and speech therapy)^[7][12]

Some therapeutic options that have been evaluated include hyperbaric oxygen therapy, certain medications, micronutrient supplements, and various rehabilitation programs^[11]. Recent studies have shown that hyperbaric oxygen, antiviral agents, and certain other medications demonstrated promising results, though more research is needed^[11].

Treatment strategies may include medication, physical therapy, counseling, memory exercises, training to restore sense of smell, and rehabilitation programs focused on lung, heart, or brain function^[15]. It is vital for healthcare providers to diagnose the syndrome early and avoid excessive testing in search of an alternative explanation^[9].

Dedicated post-acute COVID-19 syndrome clinics have been established in many healthcare centers to provide coordinated, comprehensive care for affected individuals^[1][7].

Prevention

Preventing severe outcomes from COVID-19 illness helps prevent post-acute COVID-19 syndrome^[3]. Research shows that COVID-19 vaccination is the best available tool to prevent this condition, including in children^[3].

Steps to protect yourself and others include:

• Staying up to date on COVID-19 vaccination
• Practicing good hygiene, such as handwashing
• Taking steps for cleaner air in indoor spaces
• Using precautions to prevent spread when you may have a respiratory virus
• Seeking healthcare promptly for testing and treatment if you have risk factors for severe illness^[3]

People who have not received a COVID-19 vaccine are at higher risk of developing post-acute COVID-19 syndrome^[3][15].

Living with Post-acute COVID-19 Syndrome

Experiencing or caring for someone with post-acute COVID-19 syndrome can be confusing, challenging, and frustrating^[17]. Living with this condition can be difficult and isolating, especially when there are no immediate answers or solutions^[3].

Symptoms may resolve months after illness for some people, while others may experience symptoms for years^[17]. The symptoms can range from mild to severe and may require comprehensive care. They can even result in a disability^[3]. Post-acute COVID-19 syndrome is a recognized condition that may result in a disability under the Americans with Disabilities Act^[17].

The condition can affect work life. Some estimates suggest that symptoms may prevent people from performing their job duties or require workplace accommodations^[17]. For children, it may impact their ability to attend school, complete schoolwork, or participate in sports, social activities, and other normal activities^[17].

School administrators, counselors, teachers, and nurses can work with families and healthcare professionals to provide learning or other accommodations for children with this condition^[17]. Resources are available to help patients and their families manage the physical, emotional, and financial stress associated with the condition.

Taking steps to understand each person’s unique experiences and talking with compassion can help them feel less isolated^[17]. People living with post-acute COVID-19 syndrome may experience shame or isolation about their condition, and listening to their lived experience is important^[17].

While rates of new cases have decreased since the beginning of the COVID-19 pandemic, post-acute COVID-19 syndrome remains a serious public health concern as millions of adults and children have been affected^[3].