Suffering, or pain in a broad sense, may be an experience of unpleasantness or aversion, possibly associated with the perception of harm or threat of harm in an individual. Suffering is the basic element that makes up the negative valence of affective phenomena. The opposite of suffering is pleasure or happiness.
Suffering is often categorized as physical or mental. It may come in all degrees of intensity, from mild to intolerable. Factors of duration and frequency of occurrence usually compound that of intensity. Attitudes toward suffering may vary widely, in the sufferer or other people, according to how much it is regarded as avoidable or unavoidable, useful or useless, deserved or undeserved.
Suffering occurs in the lives of sentient beings in numerous manners, often dramatically. As a result, many fields of human activity are concerned with some aspects of suffering. These aspects may include the nature of suffering, its processes, its origin and causes, its meaning and significance, its related personal, social, and cultural behaviors, its remedies, management, and uses.
The word suffering is sometimes used in the narrow sense of physical pain, but more often it refers to psychological pain, or more often yet it refers to pain in the broad sense, i.e. to any unpleasant feeling, emotion or sensation. The word pain usually refers to physical pain, but it is also a common synonym of suffering. The words pain and suffering are often used both together in different ways. For instance, they may be used as interchangeable synonyms. Or they may be used in 'contradistinction' to one another, as in "pain is physical, suffering is mental", or "pain is inevitable, suffering is optional". Or they may be used to define each other, as in "pain is physical suffering", or "suffering is severe physical or mental pain".
Qualifiers, such as physical, mental, emotional, and psychological, are often used to refer to certain types of pain or suffering.