We’re currently in the middle of a pandemic due to the new coronavirus, SARS-CoV-2. This virus causes the disease COVID-19.
People who become ill with COVID-19 can have a wide variety of symptoms. Hair loss has been reported in people who have recovered from COVID-19. The Centers for Disease Control and Prevention (CDC)Trusted Source notes hair loss as a potential long-term effect of COVID-19 that’s currently under investigation.
Below, we’ll discuss whether a SARS-CoV-2 infection can lead to hair loss, other symptoms to look out for, and when to talk with your doctor.
What does the research say?
Many reports of hair loss following COVID-19 have been seen in case studies. Because of this, how often it occurs in the larger population is currently unknown.
A November 2020 studyTrusted Source investigated late-onset symptoms of COVID-19 in a small group of 63 participants. For the 58 participants included in the analysis, 14 (24.1 percent) reported hair loss.
In this study, the average time from COVID-19 symptom onset to noticeable hair loss was 58.6 days.
Hair loss resolved in five of the 14 participants. However, nine participants were still experiencing hair loss at the time they were interviewed.
Why could COVID-19 cause hair loss?
The hair loss that’s seen following COVID-19 is consistent with a condition called telogen effluvium (TE). People with TE report hair loss that comes on suddenly. Hair typically falls out in large clumps, often while brushing or showering.
Most people who develop TE have noticeable hair loss 2 to 3 months after a triggering event. This typically affects less than halfTrusted Source of the scalp and lasts for 6 to 9 months. After this period, most people find that the lost hair regrows.
How does this relate to COVID-19? One of the potential triggers for TE is an acute illness with fever. People who’ve become ill with COVID-19 often experience fever as one of their symptoms.
Stress is another potential trigger for TE. Certainly, experiencing an illness like COVID-19 can cause both physical and emotional stress. In fact, TE has also been observedTrusted Source in some people due to the stresses of quarantining.
What’s the mechanism of TE?
Hair has different growth phases. TE happens when a stressor causes a large amount of hair to stop growing and enter into the resting (telogen) phase.
In the telogen phase, hairs rest for 2 to 3 monthsTrusted Source before being shed from your scalp to allow for new hair growth. This is why hair loss due to TE happens so long after a triggering event, such as an illness or highly stressful period.
What is hair loss?
We all naturally shed hair on a daily basis. In fact, it’s common for a person to shed 50 to 100 hairs per day.
However, sometimes the hair that’s shed isn’t replaced with new hair, eventually leading to hair thinning and bald patches. This is called hair loss.
We often think of hair loss as affecting only the scalp. However, it can occur on other parts of the body too.
The medical term for hair loss is alopecia.
Is hair loss associated with severe COVID-19?
It’s possible that hair loss may be associated with severe COVID-19. However, the extent to which this is the case and the biological mechanism behind it is unclear at this moment.
A May 2020 studyTrusted Source evaluated 175 people hospitalized with COVID-19. Researchers observed that a high amount of participants (67 percent) had androgenic alopecia. It’s important to note that there was no control group in the study.
A July 2020 studyTrusted Source compared balding patterns in 336 men hospitalized for COVID-19 and 1,605 men hospitalized without COVID-19. It found that men with the most pronounced pattern of baldness were more likely to test positive for COVID-19.
A November 2020 population study surveyed 43,565 people on topics like amount of hair loss, underlying health conditions, and COVID-19 status or outcome. It was found that hair loss was independently associated with more severe COVID-19 illness.
It’s important to reiterate that research on this topic is currently limited. Further investigation is needed to determine how hair loss may be associated with COVID-19 risk.
What are the most common reasons for hair loss?
The most common cause of hair loss is androgenic alopecia. You may also see this referred to as male or female pattern baldness.
This type of hair loss is hereditary, meaning that you can inherit it from your parents. Androgenic alopecia occurs gradually as you age and has predictable patterns for men and women.
Additional causes of hair loss can include:
hormonal changes, including those that occur during pregnancy and menopause, or due to thyroid conditions
underlying health conditions, like alopecia areata, hair-pulling disorder (trichotillomania), or scalp ringworm
stressors, as observed with telogen effluvium
iron deficiency or other nutritional deficiencies
some medications or therapies, such as those used to treat cancer, depression, and high blood pressure
grooming practices that pull on your hair (traction alopecia) or are harsh to your hair
How is hair loss diagnosed?
Often, hair loss naturally occurs as you age. But sometimes it can indicate an underlying health condition.
To determine whether hair loss is happening due to a health condition, your doctor will:
take your medical history, which can include questions about:
your family history
any preexisting health conditions
what medications you’re taking
how you groom your hair
perform a physical examination, which may include a pull test on a few dozen hairs to help determine how much hair is falling out
examine samples of your hair under a microscope
order blood tests, which can help identify health conditions that may cause hair loss