Self-injury can include a variety of self-harming behaviors – all of which are performed intentionally and without suicidal intent. Those who self-injure often use multiple methods to injure themselves.

Some self-harming behaviors, such as cutting and burning, can involve ritual-like activity that may have a calming effect on the self-injurer. This can include a preoccupation with an instrument, a designated environment (e.g., a bathroom or bedroom) or the procedure itself. Other types of self-injury, such as lip-biting, hair-pulling, scratching or picking scabs can be performed almost anywhere and at any time.

Methods such as cutting and burning are described as a subset of self-injury called self-mutilation since they cause actual disfigurement of the skin.

Types of self-injury include:

• Cutting. Use of any sharp instrument to cut the skin, causing tissue damage. Cutting is among the most common methods of self-injury. Knives, razors and shards of glass are commonly used instruments. Parts of the body affected by cutting include the arms, legs, wrists and/or chest.
  
• Burning. Use of cigarettes, lighters, matches or any item hot enough to burn the skin (e.g., hot iron). Flammable fluids (e.g., alcohol, lighter fluid) are sometimes used. Most people who burn themselves do so on their arms, legs, wrists or chest.
  
  
• Hair-pulling. Also known as trichotillomania, hair-pulling involves compulsive pulling or twisting of the hair, resulting in noticeable patches of missing hair. Areas commonly affected include the scalp, eyebrows or beard, but hair can be pulled from any part of the body. Bald spots are usually disguised with a hat, bandage or sunglasses.
  
  
• Scratching. Involves scratching one’s own skin until raw or bloody. Scratching is usually done with the fingernails, but sometimes other sharp objects are used.
  
  
• Pinching. Involves repeatedly pinching oneself to induce pain and/or injury.
  
   
• Biting. Use of one’s own teeth to cause injury. This type of self-injury involves severe and frequent biting of the lips, nails or skin, usually until blood is drawn.
  
  
• Punching. When self-harm is done with one’s own fists in an effort to cause physical harm. Areas of the body commonly affected are the head and thighs.
  
  
• Interfering with wound healing. The deliberate interruption of the healing process. This type of self-injury includes picking at scabs, poking wounds with sharp objects and the premature removal of stitches.
  
  
• Ingestion of poisons. Drinking dangerous liquids, such as bleach or detergent, in an attempt to cause illness or damage to one’s own body.
  
  
• Breaking bones. Causing one’s own bones to break. Instruments used to break bones include hammers, bricks or other heavy objects. Breaking one’s own bones is a rare form of self-injury.