What is dementia?

Dementia is the loss of cognitive functioning—thinking, remembering, and reasoning—and behavioral abilities to such an extent that it interferes with a person’s daily life and activities. Dementia ranges in severity from the mildest stage, when it is just beginning to affect a person’s functioning, to the most severe stage, when the person must depend completely on others for basic activities of daily living. The most common form of dementia is Alzheimer’s disease, which counts for approximately 75% of dementia.
Dementia symptoms vary depending on the cause, but common signs and symptoms include:
• Memory loss
• Difficulty communicating
• Difficulty with complex tasks
• Difficulty with planning and organizing
• Difficulty with coordination and motor functions
• Problems with disorientation, such as getting lost
• Personality changes
• Inability to reason
• Inappropriate behavior
• Paranoia
• Agitation
• Hallucinations

Many conditions and diseases cause dementia. Two of the most common causes of dementia in older people are Alzheimer’s disease and vascular dementia, which is caused by a series of strokes or changes in the brain’s blood supply.
Other conditions that may cause memory loss or dementia include:
• medication side effects
• chronic alcoholism
• tumors or infections in the brain
• blood clots in the brain
• vitamin B12 deficiency
• some thyroid, kidney, or liver disorders

Many of these conditions are temporary and reversible, but they can be serious and should be treated by a doctor as soon as possible.

Emotional problems, such as stress, anxiety, or depression, can make a person more forgetful and can be mistaken for dementia.