Following COVID-19 infection, symptoms typically clear up within a couple weeks for most otherwise healthy people. For others, long-lasting symptoms following COVID-19 infection can drag on for months or even years. This condition is called Post-Acute Sequelae of COVID-19 (PASC) or Post-COVID condition.
There is no official definition for this condition. People with PASC fall into one of two groups. Patients with COVID-19 symptoms lasting 4 to 12 weeks are considered to have “subacute” or “post-acute COVID-19 syndrome.” Those with ongoing symptoms beyond 12 weeks have “long COVID,” “long hauler’s syndrome,” or “post-COVID-19 syndrome.” These are considered two different stages of post-COVID conditions.
Symptoms of Post-COVID Condition
People with post-COVID condition may experience any combination of the following lingering symptoms and conditions, which may come and go or gradually resolve completely.
- Brain fog (difficulty thinking or concentrating)
- Chest pain
- Difficulty breathing
- Dizziness when standing up
- Feeling of pins and needles on the skin
- Heart palpitations
- Joint or muscle pain
- Kidney issues
- Loss of, or change in, smell and/or taste
- Menstrual cycle changes
- Persistent fatigue
- Shortness of breath
- Sleep problems
- Stomach pain
- Symptoms worsen after physical or mental exertion
Complications of Post-COVID Condition
In some cases, long COVID/PASC can affect multiple organs or trigger autoimmune conditions. Those who survived severe COVID illness are at higher risk for such complications. Multi-organ effects can involve many body systems, leading to health conditions like diabetes, heart conditions, or neurological conditions.
Who Develops Long-Haul Symptoms?
Researchers are aiming to understand why some populations develop these long-lasting conditions at higher rates and why some people never experience post-COVID symptoms.
Because PASC has no standard method of diagnosis and is often self-reported, estimates on the percentage of people who develop post-COVID conditions varies, according to the CDC.
- 13.3% report long COVID symptoms one to three months later
- 2.5% report long COVID symptoms after three months or later
- Among hospitalized COVID patients, more than 30% report symptoms six months later
Most people with post-COVID conditions had previously tested positive for COVID-19. We know that those who suffered severe COVID-19 illness, especially those who were hospitalized or needed intensive care, are more likely to report post-COVID conditions. But, some asymptomatic individuals and those who experienced mild, short-lived infection may also develop post-COVID symptoms that drag on without explanation.
People who are not vaccinated against COVID-19 may also be at higher risk of developing long-lasting symptoms following infection.
Others at higher risk include people with underlying health conditions and those who experienced multisystem inflammatory syndrome while ill with COVID-19. Post-COVID conditions are less common in children and adolescents than adults.
Diagnosis of PASC
There is no test or imaging scan to confirm that any symptoms or conditions you’re experiencing were caused by COVID-19 infection. The diagnosis of PASC is primarily based on patient-reported persistent symptoms.
If you’re experiencing such symptoms lasting longer than four weeks, see your healthcare provider. Your provider can determine to the best of their knowledge if your current symptoms were triggered by COVID-19 or if you have another unrelated medical condition requiring diagnosis and treatment.
Living with Long COVID
As of July 2021, post-COVID conditions are considered a disability under the Americans with Disabilities Act.
There is no cure for PASC, but symptoms tend to resolve themselves over time. To reduce the severity of symptoms, patients with PASC can turn to medicines and therapies that have traditionally been effective for these conditions. Such treatments include taking acetaminophen or ibuprofen for headaches, antidepressants or anti-anxiety medications for mood disorders, anticonvulsants or nerve pain medications for neuropathy, smell training for anosmia (change in or loss of smell/taste), and physical therapy aimed at increasing exercise tolerance to reduce fatigue.
Infectious disease experts also recommend that such patients make healthy lifestyle changes to improve their overall health and support the immune system. These efforts include managing underlying conditions (like cardiovascular risks, asthma, diabetes, kidney disorders), maintaining a healthy weight, getting more physical activity and quality sleep, prioritizing emotional and mental wellbeing, and developing memory tools to compensate for brain fog.
Understanding and Treating Long COVID
The exact causes of PASC are not well understood, but inflammation, immune responses to the coronavirus, low-grade viral activity, underlying health conditions, and organ damage due to COVID illness are some of the suspected triggers.
Researchers across the U.S. and around the world are studying the virus that causes COVID-19 and the mechanisms that trigger long-haul symptoms.
The American Heart Association has awarded grants to 10 U.S. research programs with the goal of unraveling the mechanisms behind long COVID. At the University of Miami’s Miller School of Medicine, a team of medical professors and researchers received a $1 million grant from the association to investigate evidence of an overzealous inflammatory response from the SARS-CoV-2 virus. The multidisciplinary research team is working with the COVID-19 Long-haulers Clinic at the Miami Veterans Affairs Healthcare System to obtain blood samples and heart and lung MRI images of 150 clinic patients. The investigation relates to previous studies of battle fatigue in military veterans, which can persist long after they return from the field.
At the Miller School’s Interdisciplinary Stem Cell Institute lab, the team is inducing a COVID-19-like response in animal lab models by infecting them with a virus that mimics SARS-CoV-2.
These collaborative research efforts will test the hypothesis that long COVID begins with low-density lipoprotein receptor viral bonding, leads to inflammation and NETosis (cell death), disrupts cholesterol balance, and culminates in a form of coronary artery disease. If they observe this pattern repeatedly in the mouse model, and if the patient samples confirm these observations, the team’s findings will help the medical community learn how to better treat long COVID patients.