Most people who get COVID-19 recover completely within a few days to several weeks. However, about one in 20 people infected with COVID-19 experience long-term symptoms that can last up to 18 months or even years after the initial infection. Anyone who was infected with the virus that causes the disease can continue to experience symptoms, including shortness of breath, chest pain, fatigue, and brain fog. In fact, millions of so-called COVID long-haulers suffer from the condition.
What is long COVID?
Long COVID involves new, returning, or ongoing symptoms that people experience more than four weeks after getting COVID-19. The condition can last for months or years and is sometimes called post-COVID-19 syndrome, post-COVID conditions, or long-haul COVID-19.
The medical term, post-acute sequelae of COVID-19 (PASC), refers to a condition in which patients continue to experience COVID-19 symptoms—or new symptoms—after recovering from the initial phase of the disease.
Symptoms of long COVID
COVID-19 causes a wide variety of symptoms because a number of factors are at play and the virus can affect all organ systems. Symptoms that linger or appear after the initial recovery may be due in part to the interplay between inflammation and the body’s immune system.
Long COVID symptoms include:
- Difficulty breathing
- Shortness of breath
- Loss of smell or taste
- Joint or muscle pain
- Numbness or tingling
- Difficulty concentrating
- Brain fog
- Sleep problems or insomnia
- Depression or anxiety
- Rapid heartbeat or chest pain
- Diarrhea or stomach pain
- Blood clots
- Hair loss
- Menstrual cycle changes
In some cases, symptoms get worse after physical activity or mental effort. Other times, it may be hard to tell if symptoms are due to COVID-19 or another medical condition, including chronic fatigue syndrome, which involves extreme fatigue that worsens with physical activity or mental effort, but doesn’t improve with rest.
A COVID-19 infection can also damage the heart, kidneys, skin, and brain. In some cases, COVID-19 may play a role in developing diabetes, heart disease, or conditions of the nervous system.
Those who are treated for COVID-19 in a hospital intensive care unit (ICU) may experience post-traumatic stress disorder (PTSD), a mental health condition triggered by an alarming event.
Brain fog is a common symptom of long COVID
We all experience brain fog from time to time—fuzzy thinking, confusion, or difficulty remembering things due to lack of sleep or the side effects of a medication. While it’s not a medical term, brain fog usually goes away on its own.
Many people who have recovered from COVID-19 experience chronic brain fog that lingers for months or years. They have recovered from the physical effects of the disease but still have trouble with their thinking and memory.
COVID-19 can harm the brain in many ways and have long-term effects on other organs. Some symptoms COVID long-haulers experience—such as insomnia, body aches, fatigue, and an inability to exercise—can impair thinking and memory. For example, it’s difficult to concentrate during the day or engage in physical activity if you have trouble sleeping at night.
Your doctor or healthcare provider can work with you to address brain fog and other cognitive symptoms of long COVID-19 that affect your day-to-day life.
Risk factors for long COVID
Anyone who gets COVID-19 can have long-term health effects, including people with no symptoms and those who had only a mild illness. However, long COVID appears to be more common in adults than in children and teens.
People who are hospitalized for COVID-19, older individuals, women, and those with preexisting health conditions are more likely to develop long COVID. In addition, your chance of developing long COVID may increase if you:
- Have a severe COVID-19 infection
- Are hospitalized or need intensive care
- Have certain medical conditions before getting COVID-19
- Experience multisystem inflammatory syndrome (MIS) while sick with COVID-19
When to seek care for long COVID
While there is no test to diagnose long COVID, if you experience symptoms more than four weeks after getting infected with COVID-19, see your doctor or healthcare provider. Be prepared to describe when you started experiencing symptoms, what makes your symptoms worse, and how they affect your day-to-day activities.
It’s possible that something else could be causing your symptoms, and your doctor can determine if you are experiencing long COVID or a different health condition.
Vaccines and boosters reduce your chances of developing long COVID
The best way to avoid long COVID is to get a COVID-19 vaccine and make sure you are up to date on your booster shots. COVID-19 vaccines and boosters are safe and effective.
In rare instances when people who are vaccinated get a breakthrough COVID-19 infection, they are 50 percent less likely to develop long COVID. Staying up to date on your COVID-19 vaccines and booster doses can dramatically lower your odds of developing a severe illness that requires hospitalization.
People who get infected but experience no symptoms and those who are fully vaccinated before the infection are often partially or fully protected from long COVID.
Researchers hope to better understand long COVID
The Centers for Disease Control and Prevention (CDC), the National Institutes of Health (NIH), and other academic institutions and research organizations are conducting studies to better understand the role vaccination plays in preventing long COVID and how many people are affected by post-COVID conditions.
Scientists are also researching how new COVID-19 variants could affect post-COVID symptoms. The goal is to help healthcare providers treat and support patients with these longer-term effects.
For now, the best way to avoid long COVID is to protect yourself from the virus by getting vaccinated and boosted.
Mayo Clinic, COVID-19: Long-term effects