There's no single cause of trichotillomania (hair pulling), but there are a number of theories about why it may occur.
Mental health problem
Trichotillomania may be a reflection of a mental health problem. Psychological and behavioural theories suggest a person may pull their hair out as a way of relieving stress or anxiety.
As trichotillomania involves compulsive behaviour, some experts think it's closely related to obsessive compulsive disorder (OCD).
OCD tends to run in families. It's thought to be caused by both biological and environmental factors, which may lead to a chemical imbalance in the brain.
Neurotransmitters are chemicals that send messages from your brain to your nervous system.
If something goes wrong with the way neurotransmitters work, it can cause problems, such as compulsive and repetitive behaviours.
Trichotillomania may be a type of self-harm, where a person deliberately injures themselves to seek temporary relief from emotional distress.
The pain associated with self-harm makes the brain release endorphins (natural painkilling chemicals), which cause a short-lived sense of wellbeing.
Self-harm is often accompanied by feelings such as:
- low self-esteem
- low mood
As well as pulling your hair out, you may also self-harm in other ways – for example, by cutting yourself.
Someone may start self-harming as a way to cope with a traumatic experience, such as sexual, physical or emotional abuse.
If you've been sexually abused, trichotillomania may be seen as a way of making yourself less attractive or less feminine (if you're female).
Making yourself less attractive confirms your negative view of yourself, and the cycle of self-loathing and self-harm continues.
Some other theories about what causes trichotillomania include:
- abnormalities in the brain – brain scans have revealed brain abnormalities in some people with trichotillomania
- genetics – an alteration in a particular gene may lead to trichotillomania in some people, and a tendency to pull hair out may be inherited
- a lack of serotonin (the "feel-good" chemical in the brain) – treatment with a selective serotonin reuptake inhibitor (SSRI), which boosts serotonin levels, has been effective in some people with trichotillomania
- changes in hormone levels – trichotillomania is more common around ages when hormone levels frequently change, such as during puberty