A disability may be physical, cognitive, mental, sensory, emotional, and developmental or some combination of these. Disabilities are an umbrella term, covering impairments, activity limitations, and participation restrictions. An impairment is a problem in body function or structure; an activity limitation is a difficulty encountered by an individual in executing a task or action; while a participation restrictions a problem experienced by an individual in involvement in life situations. Thus disability is a complex phenomenon, reflecting an interaction between features of a person’s body and features of the society in which he or she lives. An individual may also qualify as disabled if he/she has had impairment in the past or is seen as disabled based on a personal or group standard or norm. Such impairments may include physical, sensory, and cognitive or developmental disabilities. Mental disorders (also known as psychiatric or psychosocial disability) and various types of chronic disease may also qualify as disabilities. Some advocates object to describing certain conditions (notably deafness and autism) as "disabilities", arguing that it is more appropriate to consider them developmental differences that have been unfairly stigmatized by society.
A disability may occur during a person's lifetime or may be present from birth.