For whatever lovely reason,changing hormones affect how much hair you lose or keep. Pregnancy, the pill, or teenagerdom,perimenopause, and menopause are all obvious causes; things like stress and diet, and though,can send your hormones out of whack in a serious enough way to cause hair loss. Major body changes like cancer can conclude it too, which is one of the reasons it’s worth it to check in with a doctor whether you truly feel your hair is falling out—not breaking, and which I’ll get to in a minute.
Source: goop.com