What stress does to your hair

You’ve been through a few hard months. A breakup, a death, a sick relative, a job that wore you out. Then things get better. And that’s exactly when your hair starts falling out: in the shower, on the pillow, in the brush. The timing is confusing, but it’s typical: stress-related shedding usually shows up a few months after the hard time¹.

Here’s what happens in your scalp, and how to tell if that’s really what’s going on.

Why stress makes hair fall out

Each hair lives in cycles. About 85% of follicles (the small pocket in the skin that a hair grows out of) are busy growing a hair. The other 15% are resting: the hair has stopped growing, it waits two to four months, then a new hair forms and pushes the old one out².

Severe stress, physical or emotional, throws this cycle off. Lots of follicles go into rest at the same time: instead of 15% of hairs, you get 30% or more². The medical name is telogen effluvium, after that resting stage, the telogen phase¹.

The follicle isn’t destroyed. Each hair that falls out makes room for a new one, and most of the time everything goes back to normal without any treatment².

Why the shedding starts months later

Because a hair that goes into rest doesn’t fall out right away. It stays in place for weeks while the next one gets ready. The British dermatologists’ leaflet puts the shedding at about 3 months after the trigger². DermNet says 2 to 4 months³, the French Society of Dermatology 2 to 3 months⁴.

In practice, if your hair is falling out today, look at your calendar three months back. That’s often where the explanation is, even if the hard time feels like a while ago.

What kinds of stress can trigger it

“Stress” covers two things here. There’s the stress you feel: caring for a sick relative, a divorce, losing your job¹. And there’s the stress your body goes through: a high fever, surgery, recovering from an illness, giving birth¹, major weight loss or a very strict diet². The NHS also lists stress among the causes of temporary hair loss⁵.

Sometimes nothing turns up. In one in three people given this diagnosis, no cause is found². That doesn’t mean you imagined the problem, only that the trigger went unnoticed.

What the pandemic showed

Spring 2020 turned into a kind of real-world experiment. At two public hospitals in New York, in Brooklyn and Manhattan, dermatologists counted their telogen effluvium diagnoses. Between November 2019 and February 2020, they made up 0.4% of patients seen in clinic. In July and August 2020, 43 patients got this diagnosis, or 2.3%⁶.

The authors note that this peak came about 3 to 4 months after the city’s stay-at-home order, the expected delay for this kind of shedding⁶. The neighborhoods involved, mostly Hispanic, had been hit very hard by the virus.

The study has its limits, and its authors spell them out. They can’t say whether the rise came from the stress of the pandemic or from the infection itself: only two patients had been tested. They also mention possible coding errors and a bias, since the link between Covid and hair loss was already in the news⁶.

How much hair, for how long

Normally, you lose 50 to 100 hairs a day⁴; the British leaflet gives a wider range, 30 to 150². During telogen effluvium, up to half the hairs on your scalp can be affected³. The loss is spread over the whole head: you lose volume and thickness, not patches².

The shedding phase usually lasts 3 to 6 months, then regrowth begins². Once the stress has passed, most people get their volume back within 6 to 9 months¹. If the stress goes on, the shedding can go on too¹. Beyond 6 months, doctors call it chronic telogen effluvium².

What one man who went through it says

On a hair loss forum, a man describes his telogen effluvium after a period of stress and depression⁷. His story follows the dermatologists’ timeline almost to the letter.

Posted on the HairLossTalk forum⁷.

He adds that he doesn’t know yet whether it will all grow back, and that he’s waiting to see. With this kind of hair loss, the waiting is the hardest part.

Stress or pattern hair loss?

Stress doesn’t cause pattern hair loss, androgenetic alopecia. According to the French Society of Dermatology, it may play a small part in how strong it is or when it starts, but it isn’t the main cause⁸.

The two can still look alike, and sometimes happen at the same time. Telogen effluvium can also reveal pattern hair loss that was already on its way². If the shedding stops but your volume doesn’t come back, a doctor can tell the difference.

Stress can act in another way too. Some people pull at their hair, often for relief, sometimes without realizing it. This is called trichotillomania, and it also causes hair loss⁹. If that sounds like you, talk to your doctor.

What helps

Usually no treatment is needed: the hair grows back on its own, and taking medicine doesn’t speed up regrowth². The most useful thing is to look after the hair you still have.

• Brush and comb without forcing², and handle your hair gently³.
• Cut back on hot hair dryers, straighteners and curling irons².
• Avoid bleaching, relaxers and hairstyles that pull².
• Eat a balanced diet, with foods rich in iron and protein, plus fruit and vegetables².
• If your scalp shows, a volumizing shampoo or hair-building fibers add thickness while it grows back².

And when you can, deal with the source of the stress. As long as it lasts, the shedding can last¹.

When to see a doctor

Seeing when it grows back

With stress, memory plays tricks. The shedding comes months after the cause, regrowth arrives as short little hairs you don’t notice, and the mirror changes its mind with the light. It’s hard to know if things are improving.

The most reliable way is to take the same photo every week: same room, same light, same distance, hair dry. Aim at the crown and the part, where volume shows best, and your hairline, where short new hairs often appear first.

That’s what Calvap does: your last photo shows up as a see-through overlay so you can line up in the same spot, and your photos sit on a timeline. The journal also lets you note the date of the hard time, so you can find the delay later. You see whether the shedding is slowing down and whether it’s growing back. And if you see a doctor, you bring dated photos. They stay on your phone.