Dementia is a combination of several symptoms that are associated with the declining abilities of the brain and its functions. There may be a decline in thinking, memory, cognition, language skills, understanding and judgement.

Over time people with dementia worsen and may have problems controlling their emotions or behaviour. They may need the help of their family, friends or caregivers in making decisions. They may eventually become apathetic to their surroundings. The cause of dementia lies in the damage to the structure of the brain.

Dementia epidemiology

Dementia is a common condition. In England there are 570,000 people living with dementia. With the rise of the elderly population and increase in life expectancy the number of people with dementia is predicted to rise over the next three decades.
 

Usually dementia occurs in people who are 65 or over. It is rarely diagnosed in the under 40s. By the age of 80 about one in five are affected, and 1 in 3 people in the UK will have dementia by the time they die. Dementia is slightly more common in women than in men.

Types of dementia

Dementia may be of 100 different types. Some of them include:

• Alzheimer’s disease is where small clumps of protein, known as plaques, begin to develop around brain cells. This may lead to severe loss of memory over time.
• Another type is vascular dementia where there are problems in the blood supply to the brain. The brain does not receive adequate oxygen.
• Dementia with Lewy bodies is another form of dementia where small abnormal structures, known as Lewy bodies, develop inside the brain.
• Frontotemporal dementia is said to occur when frontal and temporal lobes (two parts of the brain) start shrinking. This may occur in individuals under 65 years of age. It is much rarer than other types of dementia.

Dementia and other disorders

Sometimes dementia may be accompanied by other mental disorders like mood swings, anxiety and depression and confusion.

Many other illnesses can cause dementia. These may include viral infections such as HIV, Creutzfeldt-Jacob disease, chronic heavy alcohol intake, Huntington's disease, progressive supranuclear palsy and normal pressure hydrocephalus, Multiple sclerosis and Motor neurone disease.

Prognosis or outlook of dementia

There is no cure for dementia. In most patients the symptoms worsen over time.