By now, we should all be familiar with how COVID-19 is spread, its symptoms and the immediate health risks of contracting the virus. We know that older adults and people with certain underlying conditions are at greater risk for serious health complications if they get the virus. Over the last few months, public health officials and researchers have learned a startling amount about a virus that wasn’t even on our radar a year ago.

However, there are still many things we don’t know – questions that will require more data, time and research to answer. One of those areas of uncertainty is to what extent COVID-19 causes long-term effects that may continue to impact a person’s health even after they stop having acute symptoms like fever, cough and shortness of breath.

Persistent and Chronic Fatigue a Long-Term Risk?

A growing number of people who have recovered from the initial symptoms of COVID-19 are reporting persistent fatigue even months later. This isn’t completely uncommon for viruses. For example, it may take six to eight weeks to feel 100 percent after a bad case of the flu, and we know that mononucleosis can cause persistent fatigue for several months. Of particular concern with COVID-19 is how many people are reporting these lingering health effects and their extent. One neuroscience professor in London described it like this: “I used to go to the gym three times a week. [Now,] my physical activity is bed to couch, maybe couch to kitchen.”

To understand what’s behind this persistent fatigue, scientists are looking at viruses similar to COVID-19, including SARS. Some people who recovered from SARS later developed chronic fatigue syndrome, a disorder that causes extreme fatigue during physical or mental activity and doesn’t improve with rest. It’s possible this same syndrome is one of the long-term effects of COVID-19.

One of the reasons for this persistent fatigue may be due to how the virus affects the lungs. We know that shortness of breath is often caused by lung scarring and that many people hospitalized for COVID-19 experience significant lung damage. It’s possible this damage is permanent and irreversible, similar to how COPD affects patients for life.

Potential for Lasting Damage to the Heart and Other Organs

The American Heart Association warns that the virus causes damage in two main ways: through inflammation in the body and through blood clots. Both have the potential to cause lasting damage to the cardiovascular system and other systems in the body. There are already cases of patients with heart damage that’s visible months after recovering from COVID-19, as well as cases of irregular heartbeats and other arrhythmias. Blood clots not only raise risk for heart attack and stroke, but can also affect function in the lungs, legs, liver and kidneys. The question now is how much of this damage will heal over time.

Risk for Lingering Neurological and Psychological Effects

Many other lingering post-COVID health effects have been reported, including racing heartbeat, achy joints, problems with memory and concentration and a long-term loss of smell or taste. Others report long-term headaches, dizziness, numbness, mood disorders and muscle or nerve damage. By some estimates, as many as one in three patients will experience some form of neurological or psychological after-effect from having COVID-19.

“It’s not only an acute problem. This is going to be a chronic illness,” says Wes Ely, a pulmonologist and critical care physician at Vanderbilt University Medical Center. “The problem for these people is not over when they leave the hospital.”

For now, it’s still unclear exactly how many long-term health effects COVID-19 may cause, and how common those effects are among people who recover from the virus. Studies are underway to answer these questions and others. In the meantime, the potential for long-term health effects is yet another reason to do everything we can to limit the spread of COVID-19.

Even if you are a healthy person with a strong immune system who is likely to recover from COVID-19 in the short term, getting the virus could be much worse than being sick for a couple of weeks. We urge you to take every possible precaution to protect your long-term health.