Hackensack University Medical Center, which says it treats more COVID-positive patients than any other health system in New Jersey, has issued a report saying many people have experienced excessive hair loss after contracting the virus and recovering from primary symptoms.

Hair loss typically begins several weeks to three months post-infection, said dermatologist Alexis Young in a statement with the published study. And it typically lasts six to nine months, though that can vary among individuals. Hair loss is especially prevalent among long-haul patients.

“I spent six days in the hospital being treated for the virus, and several weeks after I came home, my hair started falling out in clumps,” said Paula Diaz, a former patient at HUMC, who noted in the study that she has always had a thick head of hair. “It was devastating.”

The hair loss occurs “because of overactive inflammation in the body,” Young explained. “The inflammation can cause a shift in the hair cycle.”

Hair loss is the latest symptom in a growing list of unexpected COVID effects. Earlier this month, doctors at the Mayo Clinic noted patients with the Omicron variant suffered from night sweats.

The hospital notes that among patients who had been hospitalized with COVID, 22% were dealing with hair loss months after being discharged. Last summer, 79% of the members of the U.K.’s Institute of Trichologists said they had seen cases of “post-COVD hair loss” in their clinics.

Stress is at the heart of the issue—and it’s not just a COVID phenomenon.

“Hair loss after a stressful situation is not unusual,” Young noted. “People can experience hair loss after childbirth or a major surgery, and we’re now seeing the same results after COVID-19 infection in some people.”

Dermatologists in Texas have seen the post-COVID symptom, formally known as telogen effluvium, as well and say the hair growth cycle should reset within a year and a half.

In the meantime, patients who are experiencing post-COVID hair loss can increase their vitamin uptake and manage their stress and diet to try to control the condition.