DefinitionTrichotillomania is hair loss from compulsive pulling or twisting of the hair until it breaks off.Alternative NamesTrichotillosis; Compulsive hair pullingCauses, incidence, and risk factorsTrichotillomania is a type of compulsive behavior. Its causes are not clearly understood.It may affect as much as 4% of the population. Women are four times more likely to be affected than men.SymptomsSymptoms usually begin before age 17. The hair may come out in round patches or across the scalp. The effect is an uneven appearance. The person may pluck other hairy areas, such as the eyebrows, eyelashes, or body hair.These symptoms are usually seen in children:An uneven appearance to the hairBare patches or all around (diffuse) loss of hairBowel blockage (obstruction) if people eat the hair the