Alzheimer's disease is a progressive disease, which means that it gets worse over time.

The symptoms of Alzheimer's disease can vary greatly, but those with the disease often have one or more of the following:

• Problems with memory - this may include forgetting the names of people they know well, forgetting where they live, or even who they are. Normally, recent memories are affected first, with memories of events further in the past only affected once the condition becomes more developed. As Alzheimer's progresses, memory loss may affect memories of recent events so completely that the person appears to be living in the past - they may even think of themselves as young and not recognise their true age.
• Problems with speech and language this may include forgetting simple words, using the wrong words without noticing, or their conversation may become simplified, repetitive or irrelevant.
• Confusion - becoming confused in new surroundings or by new people, or about who or where they are. They may lose track of time so that they are unsure what day it is, or even whether it is morning or afternoon.
• Changes in mood or behaviour - becoming irritable or aggressive. As Alzheimer's progresses they may lose their normal inhibitions and begin to say or do inappropriate or antisocial things; in some cases this can include inappropriate sexual behaviour. They may lose interest in the outside world or their own care, giving up interests and hobbies, paying little attention to their personal hygiene, or forgetting to wash or change their clothes.
• Difficulty performing simple tasks difficulty doing everyday tasks such as cooking a meal. They may begin cooking and then wander away, forgetting what they were doing, or they may prepare a meal and then forget to serve it.
• Problems learning new information, ideas or skills.

It is not known exactly what causes Alzheimer's disease. Scientists think there is unlikely to be a single cause, but a number of factors that come together to trigger the disease. However, they have identified certain risk factors that increase the likelihood of developing Alzheimer's:

• Age is the greatest risk factor for Alzheimer's disease, with most cases affecting people over 65. The likelihood of developing the disease doubles every 5 years after age 65.
• Family history of the disease is a risk factor, and the risk of developing the disease is higher if a parent, sister or brother has it.
• Scientists have found some genes that are known to directly cause Alzheimer's, so that anyone who inherits them is almost certain to develop the disease, usually before age 65, and sometimes as early as their 30s or 40s. However, these genes have been found in only a few hundred families worldwide. Alzheimer's caused by these genes is known as familial Alzheimer's disease.
• Those with severe head or whiplash injuries appear to be at increased risk of developing Alzheimer's.
• Alzheimer's is a feature of Downs syndrome, and 15% of people with Alzheimer's disease have a family history of Downs syndrome. Recent research has concentrated on the gene responsible for the production of a substance called beta-amyloid protein. This protein is found in the tangled fibre masses that develop in the brain of people with Alzheimer's disease, and also in those of older people with Downs syndrome. The gene for this protein is on chromosome 21. Those with Downs syndrome have an extra copy of this chromosome in every body cell.
• Research has shown that the same factors that increase the risk of heart disease may also increase the risk of Alzheimer's. This means that those who smoke and those who have high blood pressure or high cholesterol levels may be at increased risk of developing Alzheimer's.
• Some studies suggest that remaining mentally active throughout your life, especially as you get older, reduces the risk of Alzheimer's. However, the evidence is currently inconclusive.

Environmental factors are being studied as possible causes for Alzheimer's, but so far there is no conclusive evidence that any environmental factor increases the risk of Alzheimer's. The concerns regarding aluminium causing Alzheimer's disease have largely been discounted.

Alzheimer's disease cannot be diagnosed with complete certainty during someone's lifetime. It is only after death that the plaques and tangles that are characteristic of the disease can be identified in the brain. As a result, there is no specific test for diagnosing Alzheimer's.

The disease is normally diagnosed initially from the most common symptoms, such as memory loss. Standard diagnostic tests include a full medical history, careful physical examination, and simple memory and mental ability tests that check things such as the ability to read, write or calculate.

Other tests, such as a CT or MRI scan of the brain, may be used to make sure that the person does not have a condition which can produce symptoms similar to Alzheimer's, such as other forms of dementia, or depression.

After eliminating other causes, a diagnosis of Alzheimer's disease can be made with an accuracy of about 90 per cent.

There is no cure for Alzheimer's disease, so treatment focuses on reducing and slowing down the progress of the symptoms.

There are some medicines that seem to delay the progress of the disease. The National Institute for Clinical Excellence (NICE) has reviewed three drugs - donepezil, rivastigmine and galantamine - and has decided that they are of some value in certain people with moderate Alzheimer's disease. They should be continued only if the person improves, or at least does not become worse, and the person must be reviewed every six months.

A new medicine called memantine may have the same effect for some people who have moderate or severe Alzheimer's disease. However, NICE has not yet completed its review of memantine. NICE is currently proposing that this medicine should not be available on the NHS in England and Wales as a treatment option for those with Alzheimer's disease, although no final decision has yet been taken.

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 Alzheimer's disease).

Mood-controlling drugs (tranquillisers) and other forms of medication can reduce the behaviour problems that often develop in those with Alzheimer's, including sleeplessness, wandering, anxiety, agitation and depression.

There is limited evidence that the herbal remedy Ginkgo biloba can delay the progression of dementia for some of those with Alzheimer's disease, 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 Alzheimer's, so you should encourage someone with the disease 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 Alzheimer's. 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 Alzheimer's 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. Those with severe Alzheimer's disease can do little on their own and will normally need full-time care

Support and care is the most important part of treatment for Alzheimer's disease. Many people with the condition are cared for in the community, often by a relative or friend. However, caring for a person with Alzheimer's can be very difficult. Support and advice for those caring for someone with the disease is available from the following sources:

• district nurses, who can advise on day-to-day nursing care,
• community psychiatric nurses, who can advise on caring for someone with a dementia illness,
• social services, who can help with care in the home, day-care centres, respite care and benefits,
• voluntary organisations - in most areas of the UK there are organisations that provide support and advice for carers of people with Alzheimer's disease.

The information shown here is Crown copyright and has been reproduced with the permission of NHS Direct. Last updated June 2007