Craig Mckay OnLa8TV QC8 Unsplash

In normal times, some people shed noticeable amounts of hair after a profoundly stressful experience such as an illness, major surgery or emotional traumaNow, doctors say, many patients recovering from Covid-19 are experiencing hair loss — not from the virus itself, but from the physiological stress of fighting it off. Many people who never contracted the virus are also losing hair, because of emotional stress from job loss, financial strain, deaths of family members or other devastating developments stemming from the pandemic.

“There’s many, many stresses in many ways surrounding this pandemic, and we’re still seeing hair loss because a lot of the stress hasn’t gone away,” said Dr. Shilpi Khetarpal, an associate professor of dermatology at the Cleveland Clinic.

Before the pandemic, there were weeks when Dr. Khetarpal didn’t see a single patient with hair loss of this type. Now, she said, about 20 such patients a week come in. One was a woman having difficulty home-schooling two young children while also working from home. Another was a second-grade teacher anxiously trying to ensure that all her students had computers and internet access for online instruction.

In a July survey about post-Covid symptoms among 1,567 members of a survivors’ group, 423 people reported unusual hair loss, according to the group, Survivor Corps, and Natalie Lambert, an associate research professor at Indiana University School of Medicine, who helped conduct the survey.

Dr. Emma Guttman-Yassky, the incoming chairwoman of the dermatology department at Mount Sinai’s Icahn School of Medicine, said she has treated many frontline medical workers for hair loss, including her hospital’s employees.

“Some of them had Covid, but not all of them,” she said. “It’s the stress of the situation. They were apart from their families, they worked for many hours.”

For most patients the condition should be temporary, doctors say, but it could last months.

There are two types of hair loss the pandemic seems to be triggering, experts say.

In one condition, called telogen effluvium, people shed much more than the typical 50-to-100 hairs per day, usually beginning several months after a stressful experience. It essentially involves a shifting or “tripping of the hair growth system,” said Dr. Sara Hogan, a dermatologist at the David Geffen School of Medicine at University of California, Los Angeles, who has been seeing up to seven patients a day with the condition.

In healthy hair cycles, most hairs are in a growing phase, with a small percentage in a short resting phase and only about 10 percent of hairs in a shedding or telogen phase. But with telogen effluvium, “people are shedding more, growing less,” Dr. Khetarpal said, and up to 50 percent of hair might skip ahead to the shedding phase, with only about 40 percent in the growth phase.

The phenomenon, which some women also experience after pregnancy, typically lasts about six months, but if stressful situations persist or recur, some people develop a chronic shedding condition, Dr. Hogan said. The other hair loss condition that is increasing now is alopecia areata, in which the immune system attacks hair follicles, usually starting with a patch of hair on the scalp or beard, said Dr. Mohammad Jafferany, a psychiatrist and dermatologist at Central Michigan University.

“It is known to be associated with or exacerbated by psychological stress,” said Dr. Jafferany.

Dr. Guttman-Yassky said that she has seen “a huge increase in this type of alopecia.”

Not all of the patients had Covid-19, she said, but the ones who did tended to progress very quickly from one or two bald patches to “losing hair all over the body,” including eyebrows and eyelashes. She said that might be because the storm of inflammation that some Covid patients experience elevates immune molecules linked to conditions like alopecia.

Experts don’t know exactly why stress triggers these conditions, which affect both women and men. It might be related to increased levels of cortisol, a stress hormone, or to effects on blood supply, Dr. Hogan said.

The hair loss itself can cause more stress, Dr. Khetarpal said, especially for women, whose hair is often more closely tied to identity and self-confidence.

“It’s your trademark,” said Mary Lou Ostling, 77, a retired educator who lives in the Stuyvesant Town neighborhood of Manhattan. She was hospitalized for Covid-19 for eight days in the early spring and later noticed that “my hair started coming out in chunks,” she said. “I always was clearing hair out of the comb, brush, the sink.”

Ms. Ostling said she also could tell that her hair wasn’t growing much because she wasn’t seeing roots that contrasted with the color she had previously dyed it.

“I’ve always had very long, very thick, very curly hair,” she said. But in July, “I simply had a lot of it all cut off. I couldn’t deal with it anymore.”

When she came home from the hairdresser, she said, “my husband was just staring at me. He said, ‘I think I have a different wife.’ It was very depressing.” She said she has finally begun to detect some hair growth.

Experts recommend good nutrition, vitamins like biotin and stress-reduction techniques like yoga, scalp massage or mindfulness meditation. Some also recommend minoxidil, a hair-growth drug, but Dr. Hogan warns patients that it can initially cause more hair loss before it starts working.

With alopecia areata, Dr. Guttman-Yassky said, some cases resolve without treatment and some are helped by steroid injections, but some can become permanent, especially if not treated early.

For people depressed or traumatized by hair loss, Dr. Jafferany recommends psychotherapy, but not necessarily medication because some antidepressants and anti-anxiety medications can exacerbate hair loss.

When Liz Weidhorn, 44, of Fair Lawn, N.J., who tested positive for Covid-19 in March, noticed members of an online Covid group bemoaning hair loss, she told herself that if it happened to her, “I will take it with grace and I’ll get a kick-ass hat,” she recalled.

But recently after showering, “I looked at my wet hair and I could see so much scalp,” she said, “and I couldn’t believe how emotional I got.” She cried and called her husband in to look at it.

“It’s really shocking,” she said. “It got me very sad.”

Ms. Weidhorn, who writes a blog about baking pastry, started taking biotin, had her mother cut her hair and is considering getting a headband.

Mrs. Rowe, who managed the front desk for a wellness spa, has gone further. “I tried putting my hair in one of those messy buns, but it looks terrible with the bald spots on the sides,” she said. So, she got wigs: “a really short pixie one, a pageboy one, a long curly one and a strawberry blonde one,” she said. “I’m trying to make the best of it.”

Dr. Hogan said some patients find the situation so upsetting they avoided washing or brushing their hair because they noticed the hair loss more during those activities. She tells them they shouldn’t be afraid of normal grooming.

She added, “Patients don’t like this when I say this, but they come around to it: Hair is not crucial for your survival.”

Pam Belluck is a health and science writer whose honors include sharing a Pulitzer Prize and winning the Nellie Bly Award for Best Front Page Story. She is the author of Island Practice, a book about an unusual doctor. @PamBelluck