What’s the difference between Alzheimer’s and dementia?
People often use the words Alzheimer’s and dementia interchangeably, but they’re not quite the same thing.
Dementia describes a group of symptoms that include problems with memory, thinking and problem solving. Alzheimer’s is the most common form of dementia. But there are other types, such as vascular dementia and Lewy body dementia, too.
Most people with dementia have Alzheimer’s disease. A build up of abnormal proteins in the brain which form ‘plaques’ or ‘tangles’ is seen in people with Alzheimer’s. These proteins interfere with healthy brain cells and stop them communicating properly with each other. Over time, Alzheimer’s can cause loss of brain tissue.
Symptoms include memory loss, poor spatial perception and language problems, which get worse over time.
Scientists don’t yet know the exact cause of the disease, but increasing age and family history are thought to increase your risk of the condition. However, most cases (99%) of Alzheimer’s are not inherited.
Unlike Alzheimer’s disease, where the exact cause is unknown, we do know what causes vascular dementia, which is the second most common form of dementia. It can happen when blood flow to the brain is reduced – this damages the cells there.
It can develop as a result of a blockage in the small blood vessels inside the brain. A single stroke, or a series of mini strokes can also cause vascular dementia.
Vascular dementia can lead to slowness of thought, concentration problems, personality changes and memory problems. The symptoms can be similar to Alzheimer’s disease. It also generally gets worse over time, but some medications can slow down the condition’s progression.
Dementia with Lewy bodies
Dementia with Lewy bodies (or Lewy body dementia) affects around 100,000 people in the UK. Again, the symptoms of this disease are very similar to Alzheimer’s, but it can also cause others such as hallucinations, slow movements and tremors (like those you might expect with Parkinson’s disease).
This form of dementia gets its name from Lewy bodies, which is a build up of a type of protein in the brain that’s also found in people with Parkinson’s. This can disrupt various normal functions in the brain. We don’t yet understand why Lewy bodies can also cause dementia.
Frontotemporal dementia (FTD)
Frontotemporal dementia (FTD) is quite a rare form of dementia. It’s sometimes referred to as Pick’s disease or frontal lobe dementia.
FTD affects the lobes at the front of the brain (the parts responsible for behaviour, problem-solving and emotions). It also affects the lobes on the sides of the brain which control language, and recognising faces and familiar objects.
FTD is less likely to affect the memory than Alzheimer’s disease, but can cause changes in personality, as well as behavioural and language problems.
Most forms of dementia tend to affect those over 65, but FTD is also seen in younger people. It’s one of the most common causes of early-onset dementia (see below). Most people with FTD are diagnosed when they are between 45 and 65.
Alzheimer’s mostly affects older people, but around 5% with the disease are under 65. Scientists don’t understand why most cases of early-onset Alzheimer’s or other forms of ‘young dementia’ happen at a young age, but for a small proportion of early sufferers, there may be a genetic cause. In these rare cases, it's called ‘familial Alzheimer's disease’ and multiple family members are usually affected. People who inherit these uncommon genes tend to show symptoms in their 30s, 40s and 50s.
For more information about early-onset dementia, and to find support, visit Young Dementia UK.
To make matters even more confusing, you can have more than one form of dementia. Alzheimer’s disease and vascular dementia is the most common mix, but other combinations are also possible.
Other types of dementia
Even rarer types include Creutzfeldt-Jakob disease, HIV-related cognitive impairment and Parkinson’s disease dementia.
There’s no single test for any type of dementia. But if you’re concerned you might have symptoms, your first port of call should be your GP. They will first need to rule out other conditions that could be causing the symptoms.
You may be referred to a specialist who will conduct further memory tests and explore your symptoms in detail. If any type of dementia is suspected, a brain scan will usually take place which will give the doctor an idea of what type of dementia could be causing the symptoms.
Take a look at our Diagnosing dementia page for more details.
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