Some people infected with COVID-19 experience debilitating long-term effects. This post-COVID condition is referred to by many names, including: 

  • Post-acute COVID syndrome (PACS)
  • Post-acute sequelae of COVID (PASC)
  • Long COVID
  • Long-haul COVID

To make reading about it easier, we will use the common term, long COVID. 

The term long COVID does not necessarily mean that a person is still infected with the virus. It means that they are experiencing troublesome, often debilitating symptoms that last beyond 12 weeks after the acute infection is over. Fortunately, most people get better over time and we can help manage your symptoms. 


There are numerous symptoms of long COVID and people may experience just a few, or many of them.

The most common symptoms are:

  • Anxiety
  • Body aches
  • Brain fog (forgetfulness or confusion)
  • Depression
  • Extreme fatigue
  • Headache
  • Insomnia and other sleep problems 

Other common symptoms include:

  • Change in smell or taste
  • Dizziness
  • Gastrointestinal symptoms, including diarrhea and stomach upset
  • Pounding or rapid heartbeat
  • Ringing in the ears
  • Shortness of breath

Symptoms often get better or worse from day to day. For many patients, symptoms get worse after physical or mental activity. This can make recovery especially challenging. 

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Long COVID research and peer support lead to hope and “Grit”

When research on Long COVID was in its early stages, the Post-Acute COVID Syndrome Clinic at Dartmouth Hitchcock Medical Center took a patient-centered approach to learning about, treating and supporting people with Long COVID symptoms.

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Our changing understanding of long COVID

The newness of long COVID presents daily challenges and opportunities to expand our understanding of this syndrome.

What we do know

We know that long COVID is a condition that can be managed. Even without a known cure, we can treat your symptoms and help you cope with your condition. We also know that long COVID:

  • Is a real and diagnosable reaction to SARS-CoV-2 (the virus that causes COVID-19) that continues 12 weeks or more after infection.
  • Impacts each person differently.
  • Can affect multiple organs in your body, causing a variety of symptoms.
  • Can occur even in those who only suffered a mild case of COVID.
  • Can impact young people, athletes and people accustomed to functioning at high levels.
  • Can occur among people who have received a COVID vaccine, but it is more common among those who have not been vaccinated.
  • Can occur following infection with any of the variants of the virus.
  • Does not usually cause abnormal results of common diagnostic tools, including blood tests, breathing tests, CT scans, EKGs and other heart tests, MRIs and x-rays.

We can apply what we have learned about other similar illnesses to treat long COVID. Those illnesses include encephalomyelitis/chronic fatigue syndrome (ME/CFS), dysautonomia (a disorder of the autonomic nervous system) and other post-infection syndromes. These conditions are also poorly understood. Fortunately, there are ample resources for managing their symptoms.

What we don't know

Although we know a lot about long COVID, there are many things that we don’t know, including:

  • What causes the specific symptoms of long COVID.
  • Who is most likely to get long COVID following an episode of COVID-19.
  • How to test for it. Currently, we make the diagnosis based on your medical history, symptoms and by excluding other diseases that can cause similar symptoms.
  • How best to treat long COVID. This makes it difficult for healthcare providers to know how to manage a person's symptoms. For those who suffer from it, this difficulty can be frustrating.
  • What the SARS-CoV-2 virus does to the body to trigger such significant responses. Several possible causes of long COVID's symptoms include: 
    • An overactive immune response that releases tissue-injuring substances.
    • An immune system that attacks its own organs.
    • Particles of the virus that remain active in the body.
    • Micro-clotting, which is the formation of tiny clots in the blood vessels during acute COVID infection.

Learn more about long COVID

Research into the prevention, cause and treatment of long COVID is ongoing. These resources will keep you updated on the latest findings: