Alzheimer’s disease is a type of dementia, which means it is a disease that causes a progressive decline in brain functioning. For example, in a person with Alzheimer’s disease, memory, reasoning (solving problems) and communication can be affected.[1.3] Alzheimer’s disease is the most common type of dementia, and about 1 in 20 people aged 65 years and older have the disease.
People with Alzheimer’s disease lose nerve cells and connections in their brain, which impairs their memory, language and thinking processes, and also affects how they feel and behave. It is thought that two structures in the brain called ‘plaques’ and ‘tangles’ are the main reasons that nerve cells are damaged in someone with Alzheimer’s disease.
Most people develop some plaques and tangles as they get older, but people with Alzheimer’s disease tend to develop a lot more than normal, beginning in the areas important for memory before spreading to other areas of the brain.
It is not fully understood what leads to the development of Alzheimer’s disease, but there are some things that can increase a person’s chances of getting the disease, called ‘risk factors’. Some risk factors are:[8,9]
The symptoms of Alzheimer’s disease develop slowly over time. At first it can be difficult to work out if mild memory problems are just due to getting older, or if they are because of Alzheimer’s disease. The main symptoms can be different as the disease gets worse.
There is no single test for Alzheimer’s disease. A doctor will ask questions to learn the patient’s medical history, and will usually ask the person to do some memory, thinking and language tests to check how the different areas of the brain are working. The doctor might also do a blood test, or ask for a CT or MRI scan of the brain. If the doctor is not sure if someone has Alzheimer’s disease, they might send the person to a medical specialist like a psychiatrist or a neurologist. These specialists are experts in diagnosing, caring for and advising patients with Alzheimer’s disease and their families.
Alzheimer’s disease can be divided into three main stages:[12-14]
Preclinical Alzheimer’s disease is the first stage of the disease, where changes are occurring in the brain but the patient does not have obvious symptoms.
In prodromal Alzheimer’s disease, there are small changes to a person’s abilities or behaviour, which become more obvious over time.
Alzheimer’s dementia is the final stage of the disease where the patient needs more help in carrying out their usual daily activities, and they can end up relying on nursing care or a family carer.
Every person is affected differently by Alzheimer’s disease. On average, people with Alzheimer’s disease live for between 8 and 10 years after symptoms start, but some people have lived for up to 20 years after diagnosis.
At the moment there is no cure for Alzheimer’s disease, so treatments are used to relieve symptoms and are aimed at improving quality of life. The main treatments used for Alzheimer’s disease patients are:
As well as family carers, there are many different medical professionals who might be involved in caring for an Alzheimer’s disease patient. These include the family doctor, a psychiatrist or neurologist, specialist nurses, occupational therapists and psychologists.
Research is under way to find new treatments to stop, slow or prevent Alzheimer’s disease. Most work is being done to find treatments targeting the plaques and tangles that are thought to be the main reason for the effects of Alzheimer’s disease. Another research focus is to spot the disease as early as possible and scientists are trying to understand how the disease gets worse, and what role genetic factors play.