Alzheimer’s disease is the most common cause of dementia. More than 520,000 people in the UK have dementia caused by Alzheimer’s disease and this figure is set to rise. This group of pages is for anyone who wants to know more about Alzheimer’s disease. It describes the symptoms, how it is diagnosed, and the things that increase a person’s risk of developing it. It also explains the treatments and support that are available.
What is Alzheimer's disease?
Dementia is the name for a set of symptoms that includes memory loss and difficulties with thinking, problem-solving or language. Dementia develops when the brain is damaged by diseases, including Alzheimer’s disease. Alzheimer’s disease is a physical disease that affects the brain. It is named after Alois Alzheimer, the doctor who first described it.
The brain is made up of billions of nerve cells that connect to each other. In Alzheimer’s disease, connections between these cells are lost. This is because proteins build up and form abnormal structures called ‘plaques’ and ‘tangles’. Eventually nerve cells die and brain tissue is lost.
The brain also contains important chemicals that help to send signals between cells. People with Alzheimer’s have less of some of these ‘chemical messengers’ in their brain, so the signals are not passed on as well. There are some drug treatments for Alzheimer’s disease that can help boost the levels of some chemical messengers in the brain. This can help with some of the symptoms.
Alzheimer’s is a progressive disease. This means that gradually, over time, more parts of the brain are damaged. As this happens, more symptoms develop, and they also get worse.
Dementia and the brain
Get more information on how dementia affects the brain.
Accessible versions of this information
Watch a signed version of our information about Alzheimer's Disease or listen to it in an audio version.