Dementia is an overall term for a set of symptoms that are caused by disorders affecting the brain. It can also be termed as brain failure.
Symptoms may include memory loss and difficulties with thinking, problem-solving or language, severe enough to reduce a person's ability to perform everyday activities.
Dementia involves damage of nerve cells in the brain, which may occur in several areas of the brain. Dementia may affect people differently, depending on the area of the brain affected Dementia is not a specific disease.