Self-harm is a way of expressing very deep distress. Often, people don't know why they self-harm. It's a means of communicating what can't be put into words or even into thoughts and has been described as an inner scream. Afterwards, people feel better able to cope with life again, for a while.
Self-harm is a broad term. People may injure or poison themselves by scratching, cutting or burning their skin, by hitting themselves against objects, taking a drug overdose, or swallowing or putting other things inside themselves. It may also take less obvious forms, including unnecessary risks, staying in an abusive relationship, developing an eating problem (such as anorexia or bulimia), being addicted to alcohol or drugs, or someone simply not looking after their own emotional or physical needs.
These responses may help someone to cope with feelings that threaten to overwhelm them; painful emotions, such as rage, sadness, emptiness, grief, self-hatred, fear, loneliness and guilt. These can be released through the body, where they can be seen and dealt with. Self-harm may serve a number of purposes at the same time. It may be a way of getting the pain out, of being distracted from it, of communicating feelings to somebody else, and of finding comfort. It can also be a means of self-punishment or an attempt to gain some control over life. Because they may feel ashamed, afraid, or worried about other people's reactions, people who self-harm often conceal what they are doing rather than draw attention to it.
It's worth remembering that most people behave self-destructively at times, even if they don't realise it. Perfectly ordinary behaviour, such as smoking, eating and drinking too much, or working long hours, day after day, can all be helping people to numb or distract themselves and avoid being alone with their thoughts and feelings.
Please see Understanding Self-harm link below: