Body-focused repetitive behaviors (BFRBs) are a group of conditions in which a person repeatedly touches, pulls, picks at, or bites parts of their own body in ways that cause physical damage. Hair pulling, skin picking, nail biting, cheek chewing, lip biting, and teeth grinding all fall under this umbrella. Nearly everyone engages in some version of these behaviors occasionally, but for roughly 1 in 4 people, the behaviors become frequent and severe enough to cause noticeable harm, distress, or disruption to daily life.
Which Behaviors Count as BFRBs
The two most recognized BFRBs are hair pulling (trichotillomania) and skin picking (excoriation disorder). These are the only two that currently have formal diagnoses in the DSM-5, where they’re classified under “Obsessive Compulsive and Related Disorders.” The ICD-11 similarly places them under a subheading specifically labeled “Body Focused Repetitive Behavioral Disorders.”
Several other behaviors fall under the BFRB umbrella even though they don’t yet have their own diagnostic categories:
- Nail biting (the most common BFRB, affecting about 11% of people at a clinical level)
- Skin biting (chewing or biting the skin around fingers or hands, roughly 9% prevalence)
- Skin picking (about 8% prevalence)
- Lip or cheek biting (about 8% prevalence)
- Teeth grinding
- Finger cracking and finger sucking
A large population study found that 97% of participants acknowledged at least one BFRB at some point in their lifetime. This makes mild, occasional versions of these behaviors almost universal. The clinical distinction comes when the behavior is persistent, causes tissue damage, and leads to significant distress or impairment.
What Triggers an Episode
BFRBs don’t arise out of nowhere. They typically serve a function, even if the person doing them isn’t fully aware of it in the moment. The most common triggers fall into two broad categories: emotional and sensory.
On the emotional side, these behaviors often emerge as a way to manage uncomfortable feelings like boredom, anxiety, embarrassment, or general unhappiness. Many people describe a cycle: anxiety or tension builds before the behavior, and then a sense of relief follows once they’ve picked, pulled, or bitten. That relief reinforces the behavior, making it more likely to happen again the next time tension rises. BFRBs can also function as a distraction technique during stressful or uncomfortable situations.
On the sensory side, the behavior can be driven by physical sensations. Someone might pull a hair that doesn’t “feel right” or pick at a bump on their skin they want to smooth out. This kind of BFRB is often more intentional and visually guided, like standing in front of a mirror scanning for imperfections. But many episodes happen entirely outside of awareness, while reading, watching TV, studying, or sitting at a desk. People often don’t realize they’ve been pulling or picking until they see the evidence afterward.
Both understimulation and overstimulation can set off an episode. A person who’s bored in a meeting may start biting the inside of their cheek without thinking. Someone overwhelmed by a difficult conversation may pick at the skin around their nails as a way to redirect their attention.
Why BFRBs Happen
BFRBs are not simply “bad habits” that someone can stop through willpower. They involve differences in how the brain regulates impulses and processes reward. The behaviors are currently understood to sit at the intersection of impulse control and compulsive behavior, which is why they were moved from the impulse control category (where hair pulling was originally placed in the 1980s) to the obsessive-compulsive spectrum.
The brain’s reward system plays a central role. Engaging in the behavior provides a brief but genuine neurological payoff, whether it’s the relief of tension, the satisfaction of removing something that felt “wrong,” or simply the sensory feedback of the action itself. Over time, this creates a deeply reinforced loop that becomes automatic and difficult to interrupt without targeted strategies.
BFRBs also commonly co-occur with other mental health conditions, particularly anxiety, depression, and OCD. This overlap doesn’t mean one causes the other, but it suggests shared underlying vulnerabilities in how the brain handles emotions and repetitive urges.
Physical Consequences
When BFRBs persist over months or years, they can cause real physical harm. Chronic hair pulling can lead to bald patches and, if the same follicles are damaged repeatedly, permanent hair loss. Skin picking can result in open wounds, scarring, and skin infections. Severe nail biting can damage the nail bed permanently, cause dental problems, and increase the risk of infections around the fingertips.
One rare but serious complication of hair pulling is a trichobezoar, a mass of swallowed hair that accumulates in the stomach or intestines. This requires medical intervention and can become dangerous if undetected.
Beyond the physical damage, the visible signs of BFRBs often create a secondary layer of distress. Bald spots, scarred skin, and damaged nails can lead to shame and social withdrawal. Many people go to significant lengths to hide the evidence, wearing hats, long sleeves, or bandages, and avoiding situations where the damage might be noticed.
How BFRBs Are Treated
The most effective treatments for BFRBs are behavioral therapies that help you become aware of the behavior and build new responses to your triggers.
Habit Reversal Training (HRT) is the most studied approach. It has two core components. First, awareness training, where you learn to identify the situations, times of day, and emotional states that trigger your BFRB. Second, competing response training, where you practice a physically incompatible action for one to three minutes whenever you notice an urge or catch yourself mid-behavior. For someone who pulls hair, that might mean clenching a fist or folding their hands. The idea is to replace the automatic response with a deliberate one until the urge passes. In clinical trials, roughly two-thirds of people who used HRT reported their symptoms decreased, and about 31% achieved at least a 35% reduction in severity.
Comprehensive Behavioral Treatment (ComB) takes a broader approach. Rather than focusing mainly on the competing response, it helps you map out all the factors driving your behavior: settings, thoughts, feelings, sensory triggers, and the physical movements involved. From there, you build a personalized set of strategies targeting each contributing factor. The International OCD Foundation describes ComB as one of the leading treatments for BFRBs alongside HRT.
On the medication side, one supplement that has shown promise is N-acetylcysteine (NAC), an amino acid derivative that affects how the brain processes reward signals. In a randomized clinical trial of 66 adults with skin picking disorder, 47% of those taking NAC showed significant improvement over 12 weeks, compared to 19% on placebo. NAC was well tolerated and is available over the counter, though it works best as part of a broader treatment plan rather than as a standalone solution.
How It Differs From OCD
Because BFRBs are classified alongside OCD, people often assume they’re the same thing. They share some features, particularly the repetitive nature of the behaviors and the difficulty stopping them. But there are important differences. OCD is driven by intrusive, distressing thoughts (obsessions) that compel a person to perform rituals to neutralize the anxiety. BFRBs typically don’t involve obsessive thoughts. The behavior itself is the core problem, and it’s often driven by sensory experiences or emotional states rather than fear-based thinking.
This distinction matters for treatment. Exposure and response prevention, the gold-standard therapy for OCD, isn’t the primary approach for BFRBs. Behavioral therapies like HRT and ComB are more directly targeted at the specific patterns that maintain these behaviors.