The times when I’ve pulled fistfuls of hair out of my head in the shower, my life wasn’t particularly stressful—or at least, it wasn’t until my hair started coming out. Then, of course, I assumed I was either balding or belatedly inheriting my family’s matrilineal thin hair. Faced with the stark reality of my hair-related vanity, I would try to comfort myself with the fact that I could at least wear fun wigs. You know, the natural cycle of things.
But the explanation for this actually lies in another cycle—the life cycle of a hair.
Basically, a hair grows, then stops growing, then falls out. (Revelatory, I know. But stay with me.) The growth phase, or anagen, of a human head hair can last two to six years, which is why our head hairs can get so long. Other hairs have much shorter growth phases—an eyelash’s, for example, is 30 days. After anagen, a hair goes into catagen, a very short phase lasting just a couple days, in which the follicle shrinks a little bit. That’s followed by telogen, when the hair pretty much just sits there, doing nothing. Then, at last, exogen, when it falls out.
This process is always happening, and it’s totally normal for a person to lose between 50 and 100 hairs a day this way. That’ll plug your drain up, but compared to the 90,000 to 150,000 total hairs on the average person’s head, it’s pennies.