In telogen effluvium, there is widespread thinning of the hair on the scalp. Often, the cause of the condition is unknown, but telogen effluvium may sometimes be triggered by factors such as childbirth, a severe illness, stress, or extreme dieting and weight loss.
Usually, the only symptom is increased hair loss—noticeable, for example, as more than normal amounts of hair shed when brushing, combing, or washing the hair—although sometimes the scalp may be more sensitive than normal.
Telogen effluvium does not need treatment, because the hair grows back once the trigger has disappeared.