Long-term symptoms range from neurological issues like “brain fogs” to an elevated heart rate.

One study of Italian patients, published in JAMA, evaluated patients’ symptoms several weeks after they’d been discharged from the hospital and tested negative for the virus. It found that only 12.6% of them were free of any coronavirus-related symptoms.

Common symptoms among recovered patients include fatigue, difficulty breathing, joint and chest pain, cough and headache.

Many of these patients are “younger and had previously been healthy, with Covid cases initially considered mild to moderate. But months later they are still sick, and some are getting worse,” the Wall Street Journal reports.