Alzheimer's disease is the most common form of dementia, which is a group of symptoms associated with a decline in mental abilities, such as memory and reasoning.
Alzheimer's disease attacks nerves, brain cells and neurotransmitters (chemicals that carry messages to and from the brain). Although Alzheimer’s disease is often associated with increasing age, the exact cause is unknown.
Alzheimer’s disease is a progressive condition, which means that it will continue to get worse as it develops.
Early symptoms include:
These symptoms change as Alzheimer’s disease develops, and it may lead to:
Dementia is a syndrome (a group of related symptoms) that is associated with an ongoing decline of the brain and its abilities. These include:
People with dementia may also become apathetic, have problems controlling their emotions or behaving appropriately in social situations. Aspects of their personality may change or they may see or hear things that other people do not, or have false beliefs. Most cases of dementia are caused by damage to the structure of the brain. People with dementia usually need help from friends or relatives, including help in making decisions.
Many of the symptoms of Alzheimer’s disease are similar to those of other conditions.
No two cases of Alzheimer's disease are ever the same because different people react in different ways to the condition. However, generally, there are three stages to the condition:
Alzheimer’s disease tends to ‘creep up’ on you, so you may not notice the symptoms immediately. The symptoms progress slowly over a seven- to ten-year period. However, the rate at which they progress will differ for each individual.
The three stages of Alzheimer’s disease are described below.
Common symptoms of mild Alzheimer's disease include:
These symptoms are a result of a gradual loss of brain function. The first section of the brain to start deteriorating is often the part that controls the memory and speech functions.
As Alzheimer's disease develops into the moderate stage, it can also cause:
During the moderate stage, you may have difficulty remembering very recent things. Problems with language and speech could also start to develop at this stage. This can make you feel frustrated and depressed, leading to mood swings.
Someone with severe Alzheimer's disease may seem very disorientated and show signs of major confusion.
This is also the stage where people are most likely to experience hallucinations and delusions. They may think that they can smell, see or hear things that are not there, or believe that someone has stolen from them or attacked them when they have not. This can be distressing for friends and family, as well as for the person with Alzheimer's disease.
The hallucinations and delusions are often worse at night, and the person with Alzheimer's disease may start to become violent, demanding and suspicious of those around them.
As Alzheimer's disease becomes severe, it can also cause a number of other symptoms such as:
During the severe stage of Alzheimer's disease, people often start to neglect their personal hygiene. It is at this stage that most people with the condition will need to have full-time care because they will be able to do very little on their own.
Alzheimer's disease affects a person's ability to look after themselves when they are unwell, so another health condition can develop rapidly if left untreated. A person with Alzheimer's may also be unable to tell someone if they feel unwell or uncomfortable.
Alzheimer's disease can shorten life-expectancy. This is often caused by those affected developing another condition, such as pneumonia (inflammation of the lungs), as a result of having Alzheimer's disease. In many cases, Alzheimer's disease may not be the actual cause of death, but it can be a contributing factor.