At first, Lauren Nichols tried to explain away her symptoms. In early March, the healthy 32-year-old felt an intense burning sensation, like acid reflux, when she breathed. Embarrassed, she didn’t initially seek medical care. When her shortness of breath kept getting worse, her doctor tested her for Covid-19.
Her results came back positive. But for Nichols, that was just the beginning. Over the next eight weeks, she developed wide and varied symptoms, including extreme and chronic fatigue, diarrhea, nausea, tremors, headaches, difficulty concentrating, and short-term memory loss.
“The guidelines that were provided by the CDC [Centers for Disease Control and Prevention] were not appropriately capturing the symptoms that I was experiencing, which in turn meant that the medical community was unable to ‘validate’ my symptoms,” she says. “This became a vicious cycle of doubt, confusion, and loneliness.”
As estimated 40 to 45 percent of people with Covid-19 may be asymptomatic, and others will have a mild illness with no lasting symptoms. But Nichols is one of many Covid-19 patients who are finding their recovery takes far longer than the two weeks the World Health Organization says people with mild cases can expect. (The WHO says those with severe or critical cases can expect three to six weeks of recovery.)
Because Covid-19 is a new disease, there are no studies about its long-term trajectory for those with more severe symptoms; even the earliest patients to recover in China were only infected a few months ago. But doctors say the novel coronavirus can attach to human cells in many parts of the body and penetrate many major organs, including the heart, kidneys, brain, and even blood vessels.
“The difficulty is sorting out long-term consequences,” says Joseph Brennan, a cardiologist at the Yale School of Medicine. While some patients may fully recover, he and other experts worry others will suffer long-term damage, including lung scarring, heart damage, and neurological and mental health effects.
The UK National Health Service assumes that of Covid-19 patients who have required hospitalization, 45 percent will need ongoing medical care, 4 percent will require inpatient rehabilitation, and 1 percent will permanently require acute care. Other preliminary evidence, as well as historical research on other coronaviruses like severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS), suggests that for some people, a full recovery might still be years off. For others, there may be no returning to normal.
There’s a lot we still don’t know, but here are a few of the most notable potential long-term impacts that are already showing up in some Covid-19 patients.
Melanie Montano, 32, who tested positive for Covid-19 in March, says that more than seven weeks after she first got sick, she still experiences symptoms on and off, including burning in her lungs and a dry cough.
Brennan says symptoms like that occur because “this virus creates an incredibly aggressive immune response, so spaces [in the lungs] are filled with debris and pus, making your lungs less pliable.”
On CT scans, while normal lungs appear black, Covid-19 patients’ lungs frequently have lighter gray patches, called “ground-glass opacities” — which may not heal.
One study from China found that this ground-glass appearance showed up in scans of 77 percent of Covid-19 patients. In another study out of China, published in Radiology, 66 of 70 hospitalized patients had some amount of lung damage in CT scans, and more than half had the kind of lesions that are likely to develop into scars. (A third study from China suggests this is not just for critically ill patients; its authors found that of 58 asymptomatic patients, 95 percent also had evidence of these ground-glass opacities in their lungs. More than a quarter of these individuals went on to develop symptoms within a few days.)
“These kinds of tissue changes can cause permanent damage,” says Ali Gholamrezanezhad, a radiologist at the Keck School of Medicine at the University of Southern California.
Although it’s still too early to know if patients with ongoing lung symptoms like Montano will have permanent lung damage, doctors can learn more about what to expect from looking back to people who have recovered from SARS and MERS, other coronaviruses that resulted in similar lung tissue changes.
One small longitudinal study published in Nature followed 71 SARS patients from 2003 until 2018 and found that more than a third had residual scarring, which can mean reduced lung capacity. MERS is a little harder to extrapolate from, since fewer than 2,500 people were infected, and somewhere between 30 and 40 percent died. But one study found that about a third of 36 MERS survivors also had long-term lung damage.
Gholamrezanezhad has recently done a literature review of SARS and MERS and says that for this subset of people, “The pulmonary function never comes back; their ability to do normal activities never goes back to baseline.”
Additionally, Covid-19 scarring rates may end up being higher than SARS and MERS patients because those illnesses often attacked only one lung. But Covid-19 appears to often affect both lungs, which Gholamrezanezhad says escalates the risks of lung scarring.
He has already seen residual scarring in Covid-19 patients and is now designing a study to identify what factors might make some people at higher risk of permanent damage. He suspects having any type of underlying lung disease, like asthma, or other health conditions, like hypertension, might increase the risk of having longer-term lung issues. Additionally, “the older you are, probably the higher your chance of scarring,” he says.
For people with this kind of lung scarring, normal activities may become more challenging. “Routine things, like running up a flight of stairs, would leave these individuals gasping for air,” Brennan says.
Stroke, embolisms, and blood clotting
Many patients hospitalized for Covid-19 are experiencing unexpectedly high rates of blood clots, likely due to inflammatory responses to the infection. These can cause lung blockages, strokes, heart attacks, and other complications with serious, lasting effects.
Blood clots that form in or reach the brain can cause a stroke. Although strokes are more typically seen in older people, strokes are now being reported even in young Covid-19 patients. In Wuhan, China, about 5 percent of hospitalized Covid-19 patients had strokes, and a similar pattern was reported with SARS.
In younger people who have strokes, mortality rates are relatively low compared to those who are older, and many people recover. But studies show only between 42 and 53 percent are able to return to work.
Blood clots can also cut off circulation to part of the lungs, a condition known as a pulmonary embolism, which can be deadly. In France, two studies suggest that between 23 and 30 percent of people with severe Covid-19 are also having pulmonary embolisms.
One analysis found that after a pulmonary embolism, “symptoms and functional limitations are frequently reported by survivors.” These include fatigue, heart palpitations, shortness of breath, marked limitation of physical activity, and inability to do physical activity without discomfort.
This article was originally published in Vox.