Signs and symptoms of trichotillomania often include:

• Repeatedly pulling your hair out, typically from your scalp, eyebrows or eyelashes, but sometimes from other body areas, and sites may vary over time
• An increasing sense of tension before pulling, or when you try to resist pulling
• A sense of pleasure or relief after the hair is pulled
• Noticeable hair loss, such as shortened hair or thinned or bald areas on the scalp or other areas of your body, including sparse or missing eyelashes or eyebrows
• Preference for specific types of hair, rituals that accompany hair pulling or patterns of hair pulling
• Biting, chewing or eating pulled-out hair
• Playing with pulled-out hair or rubbing it across your lips or face
• Repeatedly trying to stop pulling out your hair or trying to do it less often without success
• Significant distress or problems at work, school or in social situations related to pulling out your hair

Many people who have trichotillomania also pick their skin, bite their nails or chew their lips. Sometimes pulling hairs from pets or dolls or from materials, such as clothes or blankets, may be a sign. Most people with trichotillomania pull hair in private and generally try to hide the disorder from others.

For people with trichotillomania, hair pulling can be:

• Focused. Some people pull their hair intentionally to relieve tension or distress — for example, pulling hair out to get relief from the overwhelming urge to pull hair. Some people may develop elaborate rituals for pulling hair, such as finding just the right hair or biting pulled hairs.
• Automatic. Some people pull their hair without even realizing they're doing it, such as when they're bored, reading or watching TV.

The same person may do both focused and automatic hair pulling, depending on the situation and mood. Certain positions or rituals may trigger hair pulling, such as resting your head on your hand or brushing your hair.

Trichotillomania can be related to emotions:

• Negative emotions. For many people with trichotillomania, hair pulling is a way of dealing with negative or uncomfortable feelings, such as stress, anxiety, tension, boredom, loneliness, fatigue or frustration.
• Positive feelings. People with trichotillomania often find that pulling out hair feels satisfying and provides a measure of relief. As a result, they continue to pull their hair to maintain these positive feelings.

Trichotillomania is a long-term (chronic) disorder. Without treatment, symptoms can vary in severity over time. For example, the hormonal changes of menstruation can worsen symptoms in women. For some people, if not treated, symptoms can come and go for weeks, months or years at a time. Rarely, hair pulling ends within a few years of starting.

The cause of trichotillomania is unclear. But like many complex disorders, trichotillomania probably results from a combination of genetic and environmental factors.

These factors tend to increase the risk of trichotillomania:

• Family history. Genetics may play a role in the development of trichotillomania, and the disorder may occur in those who have a close relative with the disorder.
• Age. Trichotillomania usually develops just before or during the early teens — most often between the ages of 10 and 13 years — and it's often a lifelong problem. Infants also can be prone to hair pulling, but this is usually mild and goes away on its own without treatment.
• Other disorders. People who have trichotillomania may also have other disorders, such as depression, anxiety or obsessive-compulsive disorder (OCD).
• Stress. Severely stressful situations or events may trigger trichotillomania in some people.

Although far more women than men are treated for trichotillomania, this may be because women are more likely to seek medical advice. In early childhood, boys and girls appear to be equally affected.

Although it may not seem particularly serious, trichotillomania can have a major negative impact on your life. Complications may include:

• Emotional distress. Many people with trichotillomania report feeling shame, humiliation and embarrassment. They may experience low self-esteem, depression, anxiety, and alcohol or street drug use because of their condition.
• Problems with social and work functioning. Embarrassment because of hair loss may lead you to avoid social activities and job opportunities. People with trichotillomania may wear wigs, style their hair to disguise bald patches or wear false eyelashes. Some people may avoid intimacy for fear that their condition will be discovered.
• Skin and hair damage. Constant hair pulling can cause scarring and other damage, including infections, to the skin on your scalp or the specific area where hair is pulled and can permanently affect hair growth.
• Hairballs. Eating your hair may lead to a large, matted hairball (trichobezoar) in your digestive tract. Over a period of years, the hairball can cause weight loss, vomiting, intestinal obstruction and even death.