Most cases of Alzheimer's develop in those aged 65 or over. Below the age of 65, Alzheimers is rare, affecting about 1 person in 1000. Over the age of 65 it affects about 1 in 20. The risk of developing Alzheimers continues to increase with age, so those aged 80 have a higher risk of developing it than those aged 65. By the age of 85 nearly 1 in 2 will have the disease.

Women have a slightly greater chance of developing Alzheimers than men. About 500,000 people in the UK are believed to have the disease.

Symptoms of Alzheimers disease

Alzheimers disease is a progressive disease, which means that it gets worse over time.
The symptoms of Alzheimers disease can vary greatly, but those with the disease often have one or more of the following:

1. 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 Alzheimers 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.
2. 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.
3. 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.
4. Changes in mood or behaviour - becoming irritable or aggressive. As Alzheimers 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.
5. 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.
6. Problems learning new information, ideas or skills.

Alzheimer's disease can also cause:

1. hallucinations,
2. delusions,
3. obsessive or repetitive behaviour,
4. a belief that the person has done or experienced things that never happened (confabulation),
5. disturbed sleep, or sleeping in the daytime and being awake at night, or
6. incontinence.

As Alzheimers becomes severe, it can cause other symptoms, including:

1. difficulty swallowing,
2. difficulty changing position or moving from place to place without assistance,
3. physical deterioration,
4. loss of appetite or loss of weight,
5. increased vulnerability to infection, and
6. complete loss of short-term and long-term memory.
7. Although the symptoms of Alzheimers vary from person to person, three broad stages of the disease can be recognised - mild, moderate and severe:
8. Alzheimers usually starts with a gradual, almost imperceptible, loss of brain function. This is often noticed first as minor memory problems, similar to everyday forgetfulness, which can be compensated for by keeping memo pads and lists. However, the loss of memory often causes anxiety. Being unable to perform even simple arithmetic is another common early sign of Alzheimers disease.
9. As Alzheimers progresses it enters a moderate stage, where memory loss is more severe, often affecting the memory of recent events in particular. Sometimes, those with this stage of the disease become confused and invent events or conversations to fill the gaps in their memory (known as confabulation). There is a progressive loss of awareness of the current time or place (disorientation), with uncertainty even in familiar locations and inability to give the date or even the year. Language problems increase, with inability to find the right word (dysphasia). These difficulties can cause alarm and frustration, and this can in turn lead to sudden and unpredictable mood changes.
10. In the severe stage of Alzheimers, there is severe disorientation and confusion. There may be perception of non-existent sights, sounds and smells (hallucinations) and false ideas of persecution (paranoid delusions). These are usually worst at night. The individual may become demanding, suspicious and sometimes violent. They often start to ignore personal hygiene, and incontinence of urine and faeces is common. Those with severe Alzheimers disease can do little on their own and will normally need full-time care.

Alzheimers is considered to be a fatal disease, although the actual cause of death is usually another illness (such as pneumonia) which develops as a complication in a person already weakened by Alzheimers. Those with Alzheimers die an average of eight years after first experiencing symptoms. However, the disease progresses at different rates in different people and the duration of the disease can vary from 3 to 20 years.

Source:
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