The most common issues include cardiovascular problems and fatigue.
Less common - but still troubling - is a new one doctors are now learning about: hearing loss.
After being in the ICU for 22 days, Michael Goldsmith woke up not being able to hear.
"I had thought I was sleeping for two years." he said.
Goldsmith had clots in his leg, lost function in his shoulders and arms and had what he describes as "static" in his ears.
He was suffering from profound hearing loss.
"I can hear a little bit; it sounds like Charlie Brown's teacher is how I always describe it, you know? You can't make out any words," Goldsmith said.
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Dr. Laurie Jacobs is the co-director of the specialized COVID-19 recovery unit at Hackensack University Medical Center in New Jersey.
"I've seen very few patients, if any, complain of hearing loss - but we don't know everything about this yet," Jacobs said.
Since mid-summer, a handful of cases of hearing loss have been reported worldwide, according to the International Journal of Audiology.
Doctors in the United Kingdom say it's possible the virus enters inner ear cells and causes cell death.
Jacobs said it's possible COVID-19-related hearing loss is being overlooked or underreported.
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"It may be that people don't attribute it to COVID," she said. "Everything is on the table."
Goldsmith is working hard to get healthy. With his physical therapist, he ran his first 5K event on Thanksgiving Day.
"You're here now and that's all you have to worry about and move on from there," he said.