Self-harm (SH) or deliberate self-harm (DSH) includes self-injury (SI) and self-poisoning and is defined as the intentional, direct injuring of body tissue most often done without suicidal intentions. These terms are used in the more recent literature in an attempt to reach a more neutral terminology. The older literature, especially that which predates the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR), almost exclusively refers to self-mutilation. The term is synonymous with "self-injury". The most common form of self-harm is skin-cutting but self-harm also covers a wide range of behaviors including, but not limited to, burning, scratching, banging or hitting body parts, interfering with wound healing, hair-pulling (trichotillomania) and the ingestion of toxic substances or objects. Behaviours associated with substance abuse and eating disorders are usually not considered self-harm because the resulting tissue damage is ordinarily an unintentional side effect. However, the boundaries are not always clear-cut and in some cases behaviours that usually fall outside the boundaries of self-harm may indeed represent self-harm if performed with explicit intent to cause tissue damage. Although suicide is not the intention of self-harm, the relationship between self-harm and suicide is complex, as self-harming behaviour may be potentially life-threatening. There is also an increased risk of suicide in individuals who self-harm to the extent that self-harm is found in 40–60% of suicides. However, generalising self-harmers to be suicidal is, in the majority of cases, inaccurate..

The self is an individual person as the object of his or her own reflective consciousness. The self has been studied extensively by philosophers and psychologists and is central to many world religions.

The philosophy of self seeks to describe essential qualities that constitute a person's uniqueness or essential being. There have been various approaches to defining these qualities. The self can be considered that being which is the source of consciousness; the agent responsible for an individual's thoughts and actions; and/or the substantial nature of a person which endures and unifies consciousness over time.

The philosophy of a disordered self, such as in schizophrenia, is described in terms of what the psychiatrist understands are actual events in terms of neuron excitation but are delusions nonetheless, and the schizo-affective or schizophrenic person also believes are actual events in terms of essential being. PET scans have shown that auditory stimulation relates to certain areas of the brain and imagined similar events occur in adjacent areas but hallucinations occur in the same areas. In such cases, external influences may be the source of consciousness and the person may or may not be responsible for "sharing" in the mind's process; and/or the events which occur, such as visions and auditory stimuli, may endure and be repeated often over hours, days, months or years -- and the afflicted person may believe themselves to be in a state of rapture and/or possession, which their artistic expression may tend to confirm. Whether art has moral responsibility is difficult to relate to the idea of a unique source of consciousness and rapid thinking may lead to an insubstantial nature of the enduring person's consciousness over time; it can be said in view of these two exigencies that the person is vulnerable.

Harm is a moral and legal concept.

Bernard Gert construes harms as any of the following:

Joel Feinberg gives an account of harms as setbacks to interests. He distinguishes welfare interests from ulterior interests. Hence on his view there are two kinds of harms.

Welfare interests are

Ulterior interests are "a person's more ultimate goals and aspirations," such as "producing good novels or works of art, solving a crucial scientific problem, achieving high political office, successfully raising a family . . .".