What Is Long COVID? Symptoms, Causes, Diagnosis, Treatment, and Prevention

For most people who get sick with COVID-19, symptoms improve within a week or two. But some may experience lingering, sometimes debilitating symptoms. This is a condition that’s commonly known as long COVID, though it may also be referred to as long-haul COVID, post-COVID-conditions (PCCs), or post-acute sequelae of COVID-19 (PASC).

• General well-being: fatigue, fever, joint pain, muscle aches, changes in menstrual cycles, or worsening of symptoms after even minor physical or mental activity (post-exertional malaise)
• Heart and lungs: coughing, chest pain, difficulty breathing, shortness of breath, or fast-beating/pounding heart (heart palpitations)
• Nervous system: brain fog, dizziness (especially upon standing), headaches, sleep issues, feelings of pins and needles, loss of smell or taste
• Mental health: depression or anxiety
• Digestive health: constipation, diarrhea, and stomach pain
• Skin: rashes

Symptoms May Vary Among Racial and Ethnic Groups

Like COVID-19, long COVID is caused by a coronavirus (a type of virus) called SARS-CoV-2. Once the virus enters the respiratory system via the nose and mouth, it can multiply and infect many parts of the body. For most people, the immune system clears the virus and they fully recover. In a subset of people, however, symptoms continue or expand.

It’s not yet clear what causes long COVID — it’s still very much a mystery, says Lisa Sanders, MD, a professor of medicine and the director of the Yale New Haven Health’s Multidisciplinary Long COVID Care Center in Connecticut. “Post-infectious syndromes like COVID have been around for a really long time — as early as 1867 with the Russian flu, there was an observation of symptoms, including neurologic symptoms, that impacted people’s ability to work and do other things,” she says. “There’s a lot to learn here, and I think we’ve barely scratched the surface.”

• Organ damage from the initial infection
• Complications related to dysregulated inflammation in the body
• Dysfunction of the small blood vessels in the heart (microvascular dysfunction)
• Ongoing viral activity
• Autoimmunity
• Inadequate antibody response

In many cases, people with long COVID have other underlying conditions, which could also influence how the condition presents and their specific symptoms.

• Persistent viral remnants: After initial infection, traces of the virus may linger in hidden tissues, sparking long-lasting inflammation. Studies show viral material in various tissues, often inaccessible for standard testing.
• Autoimmunity: The body's immune system may mistakenly target its own proteins, triggered by SARS-CoV-2 infection, leading to organ damage and ongoing immune responses.
• Reactivation of dormant viruses: Latent viruses like Epstein-Barr and varicella zoster can awaken during illness, potentially worsening symptoms and activating immune responses.
• Changes in tissue inflammation: COVID-19 can alter tissue inflammation, impacting organs and the brain, possibly leading to cognitive issues like brain fog.

Understanding these theories could help guide treatment strategies.

• Asthma
• Type 2 diabetes
• Obesity
• Preexisting depression
• Hypothyroidism
• Hospitalization with acute COVID-19
• Multiple symptoms during the acute infection

But other risk factors may come into play, as well.

Being of older age, female sex, having less income or education, belonging to an ethnic minority, and not being vaccinated against the virus are also associated with a greater risk of long COVID.

The presence of certain symptoms during acute COVID-19, such as shortness of breath, fatigue, headaches, loss of smell, and muscle aches, are also associated with a greater risk of long COVID.

Currently, no specific diagnostic test exists to confirm whether someone has long COVID.

How long the symptoms of long COVID last varies from person to person. Most recover within three to six months, while others may continue to have symptoms for years.

There is no specific treatment for long COVID — yet.

That said, ongoing research in the United States and abroad may lead to better understanding the disease process of long-term COVID and other post-viral illnesses, says Hector Bonilla, MD, the codirector of the Stanford Post-Acute COVID-10 Syndrome Clinic in Palo Alto, California. From there, new therapies may emerge that target the different and specific processes causing the disease, he says.

But for now, existing treatments are used off-label to manage and treat the symptoms of long COVID, says Dr. Bonilla.

For example, someone who experiences brain fog may be referred by their doctor for cognitive rehabilitation, akin to physical therapy for the brain. During the rehab they might be taught ways to improve concentration or memory, or learn strategies to compensate for problems with thinking, says Dr. Sanders.

People who have long COVID can be treated by their general practice physician or by individual specialists for the body parts affected by their condition, such as a cardiologist for heart issues.

Sanders suggests finding a doctor who is “open-minded and thoughtful” — one who can think outside the box to find ways to treat long COVID symptoms.

You may be more likely to find those types of providers in clinics dedicated to long COVID care. These long COVID clinics are opening around the country, and many are affiliated with large community or academic hospitals. The Long COVID Alliance offers a list of long COVID clinics in the United States. Still, the ratio of clinics to people grappling with symptoms is low, so many clinics have waiting lists.

The outlook for people with long COVID varies from person to person. Some people may have symptoms that last a few weeks or months before they return back to their pre-COVID state. For others, recovery could feel like “two steps forward, one step back,” with symptoms that go away only to return again later.

Several serious medical conditions have been documented as occurring after a person recovers from an acute bout of COVID.

Diabetes

Heart Disease

Neurological Conditions

Mental Health

Long COVID can take a toll on mental health and emotional well-being. Some of the most prevalent mental health symptoms related to long COVID include anxiety, depression, and sleep disorders.

The best way to prevent long COVID is to avoid getting sick in the first place. While that may not always be possible, there are steps you can take to protect your health.

Sanders also continues to wear a mask (when possible) while traveling and when around people she doesn’t know. “I’m not afraid of getting COVID — I’m only afraid of getting long COVID,” she says.

But it may impact some groups more than others.

Women Are More Likely to Get Long COVID Than Men

Middle-Aged People Have the Highest Rates

Long COVID Affects Children, Too

People with long COVID and those who have recovered from the condition have launched a number of online support groups and resources, sometimes working alongside scientists on research investigations.

These groups provide information, guidance, emotional support, and the knowledge that no one with long COVID has to face it alone.

Some of the largest groups include:

• The MIGHTY
• Long COVID Alliance
• Long COVID Kids
• Black COVID-19 Survivors Alliance (BCS Alliance)
• Long COVID Support Group
• Long COVID Families

Long COVID occurs when people experience persistent symptoms ranging from fatigue and brain fog to cough and breathing difficulties after their initial COVID-19 infection. These symptoms can last anywhere from a few weeks or months to years. Treatments are available to help manage various symptoms. But taking steps like getting vaccinated can help prevent you from getting sick with the virus to begin with and lower your risk of developing long COVID-related health complications.

Additional reporting by Meryl Davids Landau.