There is a great difference in severity between mild and severe dementia and it can take many years to progress from mild to severe. It is not a disease, but a group of symptoms that may accompany some diseases or conditions affecting the brain.
There are many different types of dementia, each with their own causes. The most common dementia symptoms include loss of memory, confusion, and changes in personality, mood and behaviour. Dementia usually affects older people and becomes more common with age. About 6 in 100 of those over the age of 65 will develop some degree of dementia, increasing to about 20 in 100 of those over the age of 85. Dementia can develop in younger people but is less common, affecting about 1 in 1,000 of those under 65.
Although most of the people who develop dementia are over the age of 60, its important to remember that dementia is not a normal part of growing old, and most older people never develop dementia.
If you suspect you may have dementia, take a look at the "Worried about your memory?" booklet.
For information on power of attorney, guardianship and adults with incapacity act, visit the Mental Health Legislation section of elament.
In most cases, the symptoms of dementia progress gradually, often over a period of several years. The early signs - usually memory problems - are normally subtle and may not be immediately obvious.
The symptoms of dementia can vary greatly, but those with dementia often have one or more of the following:
Some types of dementia can cause less common symptoms, including:
If dementia becomes severe, it can cause other symptoms, including:
Sometimes, those with dementia are unaware that they have any symptoms, especially symptoms that affect behaviour.
Many conditions (such as depression) have symptoms similar to dementia, so it is important not to assume that someone has dementia just because they have some of the symptoms above.
Dementia develops when cells in the parts of your brain involved with mental ability become damaged. Damage to these cells can be caused by:
The most common type of dementia is that caused by Alzheimer's disease, which is responsible for about 60% of all cases. The cause of Alzheimer's disease is unknown, except for a very small percentage of cases that are inherited.
About 20% of all cases of dementia are vascular dementias, the name given to dementia caused by poor circulation of blood in the brain. There are a number of different types of vascular dementia, the most common being multi-infarct dementia, where the small blood vessels in the brain becoming narrowed or blocked. The cells in the brain supplied by these blood vessels become starved of the blood and oxygen they need, and become damaged or die. This is like having a series of small strokes in the brain.
The risk of developing vascular dementia is increased by the same things that increase the risk of stroke and heart disease. These include high blood pressure, diabetes, smoking, poor diet and excessive alcohol intake.
Other less common types of dementia include:
Dementia usually develops slowly, with mild early symptoms, so diagnosing dementia in its early stages can be difficult. It is normally diagnosed initially by the most common symptoms, such as memory loss. The diagnosis can be confirmed with a careful physical and mental examination and simple memory and mental ability tests that check things such as the ability to read, write or calculate.
However, as different types of dementia have similar symptoms, it can be more difficult to diagnose the precise type or cause. Blood tests, X-rays, or a CT or MRI scan of the brain may be necessary to provide more information.
Further tests may be needed to make sure that the person does not have a condition which can produce symptoms similar to dementia, such as depression or a severe urine or chest infection.
As those with dementia are often unaware they have a problem, many people with dementia are brought to medical attention by a caring relative or friend.
Most types of dementia cannot be cured. The exceptions are:
Alzheimers disease cannot be cured. However, for some people in the early and middle stages of the disease, the medicines donepezil, rivastigmine and galantamine may help prevent some symptoms from becoming worse for a period of time. A new medicine called memantine may have the same effect for some people who have moderate or severe Alzheimers disease.
Medical researchers are currently investigating other medical treatments, including anti-oxidants, brain stem cell therapy and a vaccination to stop the build up of plaques in the brain (a hallmark of Alzheimers disease).
There is some evidence that the herbal remedy Ginkgo biloba can delay the progression of dementia for some of those with Alzheimer's disease or vascular dementia, and even make a small improvement in symptoms such as forgetfulness and confusion. However, more research is needed.
It is thought that mental activity can help to slow the progress of some types of dementia, so you should encourage someone with dementia to stay mentally and physically active and ensure their environment is stimulating. Puzzles, games (particularly memory games), reading and simple mental arithmetic are good choices, but its important not to overwhelm them with too many demands, or unrealistic demands, as this may only frustrate them.
A technique called reality orientation may help some people with dementia. It uses repetition to help the memory and involves regularly reminding the person of information such as the time, date, where they are and important information for that day, such as a visit to see a friend. The information could be given verbally by a carer, or be written on a board in their home where they will see it regularly. The aim of reality orientation is to help people understand their situation by reminding them or telling them about what's going on.
Many of those with dementia in the early and intermediate stages are able to cope well in their own home, due to the familiar surroundings. Others may need more frequent supervision, full time care in the home, or care in a residential or nursing home.
Support and care is the most important part of treatment for dementia. Many people with dementia are cared for in the community, often by a relative or friend. However, caring for a person with dementia can be very difficult. Support and advice for those caring for someone with dementia is available from the following sources:
There is no known way to prevent Alzheimer's disease, the most common cause of dementia. However, you can reduce the risk of vascular dementia by maintaining a healthy lifestyle, including:
The information shown here is Crown copyright and has been reproduced with the permission of NHS Direct. Last updated June 2007.