Among the many unexpected issues people have faced during the COVID-19 pandemic is hair loss.

Its cause? In a word: stress.

The type of hair shedding associated with COVID-19 is called telogen effluvium (TE), says Purvisha Patel, MD, a board-certified dermatologist in Memphis, Tennessee, and founder of Visha Skincare. TE is a result of a major stress on the body, and it happens in response to mental and physical stress.

The tumult caused by the pandemic is enough to trigger it. But if you developed a COVID-19 infection, you might have gotten a double whammy, because TE can also result from the physical stress of an illness. What’s more, because the pandemic has lingered so long, and TE has been on an upsurge throughout, hair regrowth may be impacted, says Dr. Patel.

How COVID-19 Stress Contributes to Hair Loss

To understand TE, you have to understand hair cycle. The hair cycle growing phase is called anagen, the resting phase is called telogen. “At the end of the telogen, the hair falls out and the cycle resets back to anagen, the growing phase,” explains Shani Francis, MD, a board-certified dermatologist and hair loss specialist in Evanston, Illinois.

But when an acute, powerful stressor comes in, that cycle can be disrupted. Hair prematurely shifts into the resting phase and falls out. Common triggers include childbirth, hospitalization, surgery, rapid weight loss, and severe and abrupt stressors, says Dr. Francis.

“Shifting hair to rest is potentially part of our body’s sophisticated energy conservation system,” explains Francis. The theory is that it takes a lot of energy for your body to grow hair. When deep in stress, your body needs to shuttle resources toward survival — not keeping your locks luscious.

The time frame can be insidious. Due to the length of a hair cycle, TE may be happening, but not make itself obvious until about three months after extreme stress. It’s the same reason people who gave birth might notice hair falling out three months after welcoming the baby.

And while that cause may be fairly obvious or predictable, it can be difficult to pinpoint other things that trigger TE when it happens on a delay. If you’re noticing shedding, ask yourself: Did something remarkable happen three or four months ago?

How COVID-19 Infection Could Trigger Hair Shedding

A COVID-19 infection could also cause the type of hair shedding seen with TE. “COVID-19 affects the whole body, but it seems that the stress from lack of oxygenation to the hair follicles, the fever, and the stress on the body can push hair follicles into the resting phase,” says Patel.

In a study published in The Lancet in January 2021 that looked at the long-term consequences of a COVID-19 infection in people who were hospitalized, six months after their infection, the most common lingering symptoms included fatigue or muscle weakness (63 percent), sleep problems (26 percent), and anxiety or depression (23 percent). However, 22 percent also experienced hair loss.

No matter the reason behind TE-related hair shedding, the results can be dramatic, especially after washing or brushing your hair. “Since the follicles are loose and the full length of the hair falls out easily,” says Patel. For some, hair will appear as if it’s coming out in clumps. You may not notice the thinning until you lose a lot of hair, she adds.

How to Combat COVID-19 Hair Loss

The good news is that TE is temporary. The unfortunate news is that you often have to wait it out in order for your hair cycle to return to the anagen or “growth” phase, which usually takes six to nine months, according to the American Academy of Dermatology (AAD). “Usually, by the time the hair falls out, the body is already beginning to reset, as long as there are no additional changes or triggers,” says Francis.

In the case of COVID-19, the sheer length of the pandemic may be making this return to normalcy more complex, however. “Long-term stressors can shift hair into a chronic TE,” notes Patel. For that reason, you will want to make sure that you are consuming a diet that supports hair health and growth, which means a balanced diet that includes adequate protein, vitamin D, and iron, she says.

If you’ve been shedding hair, and it’s not getting better, however, despite time and these efforts, you might consider seeing a board-certified dermatologist who will evaluate you for other medical conditions that can trigger hair loss, which may include hormonal imbalances, nutritional deficiencies, or genetic causes. Your dermatologist may also recommend starting a topical minoxidil product (such as Rogaine) while waiting for your TE to correct itself to encourage more hair growth.

You’ll know hair is growing back when you see short “baby” hairs around your hairline, says the AAD. Those are typically unruly and difficult to style, and you may want to experiment with how to pin them back or different ways to wear your hair while they’re coming in. Francis also recommends reevaluating hair products to make sure they’re suited for your hair volume and thickness while your transitioning through stages of thickness.