The most common type of stress-induced hair loss is telogen effluvium. In this condition, emotional or physical stress — related to a death in the family, pregnancy, severe weight loss or surgery, for example — pushes large numbers of growing hairs into a resting phase. Within a few months, the affected hairs may fall out suddenly when simply combing or washing your hair. The hair typically grows back when the emotional or physical stress is resolved, although this can take months.
For some people, intense stress may trigger a type of hair loss called alopecia areata. In this condition, white blood cells attack the hair follicle — which stops hair growth. Within weeks, the affected hair falls out. The hair loss usually starts as a small round patch but may eventually spread to the whole scalp, and sometimes to body hair as well. The hair generally grows back, but the cycle may repeat itself.
Talk to your doctor if you notice sudden or patchy hair loss or more than usual hair loss when combing or washing your hair. Sudden hair loss can signal an underlying medical condition that requires treatment. If needed, your doctor may suggest treatment options for the hair loss as well.