While most people recover from a COVID-19 infection within weeks, many experience lingering health problems. This condition, where symptoms persist or new ones develop long after the initial illness, is known as long COVID, or medically as Post-Acute Sequelae of SARS-CoV-2 (PASC). It is considered long COVID when symptoms continue for at least four weeks after the initial infection.
The experience of long COVID is not tied to the severity of the initial infection, as individuals who had mild or even no symptoms can develop long-term issues. The condition manifests differently from person to person, and symptoms can fluctuate, sometimes disappearing and then reappearing. Researchers are still working to understand the precise mechanisms behind why the virus causes such a wide array of ongoing health problems.
Respiratory and Cardiovascular Complications
The virus that causes COVID-19 can lead to lasting issues within the respiratory and cardiovascular systems. For the lungs, this can manifest as persistent shortness of breath and a chronic cough. In some cases, after severe pneumonia, the tiny air sacs in the lungs can become damaged, leading to scar tissue. This condition, known as pulmonary fibrosis, can cause long-term breathing difficulties.
The cardiovascular system is also vulnerable to long-term effects. Inflammation of the heart muscle, a condition called myocarditis, has been observed in individuals recovering from the virus. People with long COVID report symptoms like heart palpitations, chest pain, and dizziness. These symptoms can be part of postural orthostatic tachycardia syndrome (POTS), which involves a rapid heart rate upon standing and has been linked to long COVID.
The causes for these heart-related problems are complex and may involve microscopic blood clots or an autoimmune response where the body attacks its own heart muscle cells. Studies show that even mild infections can result in inflammation in the heart and lungs. This persistent inflammation may place individuals at a higher risk for developing future cardiac conditions, such as heart failure or pulmonary hypertension. Research indicates that people with long COVID are more than twice as likely to develop new cardiovascular issues compared to those who never had the virus.
Neurological and Cognitive Impairments
The impact of long COVID extends to the brain and nervous system, leading to symptoms referred to as “brain fog.” This term describes a state of persistent mental cloudiness and encompasses a range of cognitive difficulties:
- Problems with memory
- Difficulty concentrating
- Slowed thinking
- Challenges with executive functions like planning and decision-making
These cognitive issues can affect daily life, making simple tasks like reading or following a conversation feel mentally exhausting. Individuals report trouble finding the right words and an inability to multitask, which can impact work and social interactions. Theories on the cause point to inflammation in the brain (neuroinflammation), damage to small blood vessels, or chronic reductions in oxygen levels from the acute illness.
Other neurological symptoms include persistent headaches, dizziness, and a lingering loss or distortion of smell and taste. Sleep disturbances, such as insomnia, are also reported and can worsen other cognitive symptoms. For most people, these neurological issues tend to improve over time, though for some they can persist much longer.
Systemic and Musculoskeletal Issues
Many symptoms of long COVID are systemic, affecting the entire body. A primary symptom is a profound fatigue that is not alleviated by rest. This is distinct from normal tiredness; it is an overwhelming exhaustion triggered by minor physical or mental exertion, a phenomenon known as post-exertional malaise. This type of fatigue can be incapacitating for those who experience it.
Alongside fatigue, widespread musculoskeletal pain is common. People with long COVID report persistent joint pain (arthralgia) and muscle aches (myalgia). Studies show a high percentage of individuals with long COVID experience these symptoms. The pain can occur in any muscle and has been associated with higher body mass index and being female.
Other systemic issues can include digestive problems, such as nausea, diarrhea, and stomach pain, as well as skin conditions like rashes. The cause for these widespread symptoms is thought to be related to systemic inflammation and immune system dysregulation. Research suggests an imbalance in gut bacteria following the infection may also contribute to this systemic inflammation.
Mental and Emotional Health Toll
Living with a chronic illness like long COVID takes a toll on mental and emotional well-being. This is distinct from the direct physiological effects on the brain, like brain fog, and relates more to the psychological response to the condition. High rates of anxiety, depression, and post-traumatic stress disorder (PTSD) have been reported among people with long COVID.
Anxiety stems from the uncertainty of recovery, worry about persistent physical symptoms, and the financial and social disruption the illness causes. Depression can develop from the ongoing struggle with symptoms, the loss of ability to participate in once-enjoyed activities, and feelings of hopelessness. For some who experienced a severe initial infection, PTSD can manifest.
The physical symptoms and emotional strain can lead to social withdrawal and isolation, worsening mental health. The U.S. Department of Health and Human Services has recognized that long COVID can have serious effects on mental health for both the individual and their families. The struggle is compounded by a lack of understanding from others who may not appreciate the severity of the symptoms.
Navigating Recovery and Medical Research
Recovery from long COVID is complex and requires a personalized approach, as no single treatment works for everyone. Management involves a multidisciplinary team of healthcare professionals to address the wide range of symptoms, such as cardiologists, pulmonologists, and neurologists. Physical therapy and rehabilitation are part of the plan but must be carefully managed to avoid triggering post-exertional malaise.
A strategy for managing fatigue is “pacing,” which involves balancing activity and rest to conserve energy and prevent symptom flare-ups. For mental health challenges, therapies like cognitive-behavioral therapy (CBT) can be effective. Support groups can also provide a sense of community and reduce feelings of isolation by connecting individuals with similar experiences.
The scientific community is engaged in a major effort to understand the underlying mechanisms of long COVID and develop effective treatments. The National Institutes of Health (NIH) launched the RECOVER initiative, a research program dedicated to studying the condition. This initiative involves large observational studies and clinical trials to test potential treatments, including drugs and other therapies. Researchers are investigating various theories, from persistent viral reservoirs to autoimmune responses, to find answers for those affected.