3. Alopecia Areata
Alopecia areata causes hair to fall out in startling patches. The culprit is the body’s own immune system, which mistakenly attacks healthy hair follicles. In most cases, the damage is not permanent. The missing patches usually grow back in six months to a year. In rare cases, people may lose all of the hair on their scalp and body.
Some women may notice their hair seems fuller during pregnancy. That’s thanks to high levels of hormones that keep resting hairs from falling out as they normally would. But it doesn’t last forever. After childbirth, when hormone levels return to normal, those strands fall out quickly. This can mean a surprising amount of hair loss at one time. It may take up to two years for hair to return to normal.