Dementia is the term used to describe a set of symptoms that occur when the brain is affected by disease.
What is dementia?
The word dementia describes a set of symptoms that may include memory loss, difficulties with thinking, problem-solving or language, and often changes in mood, perception or behaviour.
This is the most common type of dementia, in which abnormal proteins cause brain cells to die. Early symptoms are often to do with memory loss.
The second most common type of dementia. It occurs when the blood supply to the brain is interrupted, such as after a stroke, and causes problems with thinking and planning.
Dementia with Lewy bodies
This type of dementia gets its name from tiny spherical structures that develop inside nerve cells. Symptoms often include fluctuating alertness, hallucinations and problems with movement.
In frontotemporal dementia, damage occurs first in the front and sides of the brain. Personality, behaviour or language are initially more affected than memory.
Prions are infectious agents that attack the central nervous system and then invade the brain, causing dementia. The best-known prion disease is Creutzfeldt-Jakob disease, or CJD.
People who get dementia before they are 65 are said to have ‘young-onset dementia’. They may face different challenges to older people, partly because of their age.
Alcohol-related brain damage (including Korsakoff's syndrome)
ARBD is a brain disorder usually caused by heavy drinking over a long period. Although it is not strictly speaking a type of dementia, people with the condition experience similar symptoms.
HIV-associated neurocognitive disorder
People with HIV and AIDS sometimes develop cognitive impairment, particularly in the later stages of their illness.
Mild cognitive impairment
Mild cognitive impairment (MCI) is a condition in which someone has minor problems with cognition - their mental abilities such as memory or thinking.
Learning disabilities and dementia
People with learning disabilities, particularly those with Down's syndrome, are at increased risk of developing dementia.