To keep the answer simple: Yes, stress can cause hair loss. “Significant stress can lead to shedding and hair loss,” board-certified dermatologist Christine Shaver, M.D., FAAD, of Bernstein Medical Center for Hair Restoration in New York City tells mbg.
Stress causes a spike in the hormone cortisol (which is why it’s called the “stress hormone”). When excessive cortisol is present in the body, it can wreak havoc: With hair, it can force the hair to enter and stay in resting phase (telogen) as nutrients are redirected to other, more vital areas of the body. (It’s actually a survival mechanism.)
This was shown in a recent study done on mice, where researchers studied corticosterone levels (which is the equivalent to our cortisol) as they related to hair growth. They found that chronic and prolonged stress meant that the mice’s hair follicles stayed in resting phase1.
However, you likely won’t notice this hair loss right away. “When high stress occurs, the hair begins to shed about three to six months later,” Shaver explains. “It will continue to shed until the underlying cause of stress has been addressed and resolved,” she says.
One of the hardest parts about hair loss is the cyclical pattern—stress leads to hair loss, which can lead to more stress, more loss, and it goes on. This is why stress management is so important—more on that in a bit.