Alzheimer's disease has been hitting the headlines quite a bit recently, partly due to the fact that well known and best selling author Terry Pratchett OBE has a form of the disease and partly because recent research has highlighted that the number of people developing Alzheimer's disease is on the increase. However, many people are still unaware of what Alzheimer's disease actually is, what to expect if you or someone close to you is diagnosed with it, and how to spot the early warning signs.

What is Alzheimer's disease?

Alzheimer's disease was first described in 1906 by German neurologist Alois Alzheimer. It is a progressive disease affecting the brain that ultimately ends in death. Over time, plaques and tangles develop and the brain deteriorates and atrophies due to a loss of neurons and synapses in the cerebral cortex and some sub-cortical regions of the brain. As the disease and the subsequent brain damage progresses, the symptoms become more and more severe. How long the process takes from onset to death can vary considerably from person to person.

How common is it?

It is in fact the most common form of dementia affecting as many as 5 million Americans and just over 400,000 people in the UK and approximately 24 million people worldwide.

What causes it and who gets it?

Alzheimer's disease is generally associated with elderly people as it often begins over the age of 65, and the greater the age, the greater the risk, however, there is also an early form of Alzheimer's disease that is relatively rare but which progresses more rapidly.

Both men and women can develop Alzheimer's but women seem to be slightly more at risk than men. Other risk factors include medical conditions affecting the heart and arteries, environmental factors such as smoking, and diet. There isn't a definitive cause; nether is there an established genetic link, although research is currently being done in this area as some families do seem to show a genetic tendency, particularly if two direct relatives have the disease. Other environmental causes that have been suggested in the past include exposure to magnetic fields, or to aluminium, but these have never been scientifically validated.

What are the early signs and symptoms?

The most common early symptom reported is memory lapses. Although some memory loss is perfectly normal as we age, in people with Alzheimer's disease there is a much faster decline as well as other cognitive problems that become increasingly evident.

It is usually the sufferer's family and friends that will first notice that someone isn't behaving in the way that they used to. For example, short term memory lapses become more common and the individual finds it difficult to concentrate on tasks that they once found easy. Personality changes may become evident as well as problems with communication.

Early signs and symptoms of Alzheimer's disease can include any or all of the following:

- Confusion

- Apathy

- Avoiding social contact

- Irritability and anxiousness

- Forgetting names and places on a regular basis

- Repeating oneself often in a short space of time

- An inability to get organised, plan and think coherently

- Difficulty with daily routine tasks and making decisions

- Difficulty with arithmetic, reading, writing and other cognitive tasks

- May become disorientated in familiar places

- Indulging in strange behaviour

It is important to note that these symptoms do not necessarily indicate that someone is in the early stages of Alzheimer's disease as these same symptoms can occur as a result of other completely unconnected factors.

In the early stages, an individual may be able to compensate quite well for these problems and will continue to live and work independently for some time. However, the nature of Alzheimer's is that the symptoms will always get progressively worse, severe dementia is inevitable.

What is the prognosis?

There is no cure for Alzheimer's disease so treatment is of a palliative nature. As the disease progresses, an individual's ability to function independently will decline until eventually they lose control of their mental faculties and all bodily functions. If the disease is diagnosed early, then there is some evidence that with a good diet and the right kind of support and care, it may be possible to delay the progression of the disease; however, this is not conclusive.

One of the most devastating aspects of this disease is the effect it can have on family and friends who are forced to watch their loved one deteriorate to the point that they no longer recognise them. Indeed, there is a higher rate of depression amongst carers of people with Alzheimer's disease than those with Alzheimer's themselves.

Many people with Alzheimer's stay at home, particularly in the early stages, and are cared for by family. There is a great deal that can be done on a practical basis to ensure that the individual suffering from Alzheimer's remains as independent as possible for as long as possible, as well as help and support available for those who care for them. There are a number of organisations that have been set up with the primary aim of doing just that. You can find out more information about what is available in your area by speaking to your doctor or other health care professional.