Dementia is the term given to a set of symptoms that occur when cells in the brain stop working normally. There are different types of dementia and they can share similar symptoms, which makes diagnosing the different types of dementia complicated.
Common symptoms of dementia include memory loss, difficulty communicating, confusion, and sudden mood changes. Dementia can be stressful and frightening for both the patient and the people who love them. Unfortunately dementia is non-reversible, but early diagnosis can help give more time to make plans for patient care, and to ensure dementia patients receive the right type of support for their needs as soon as possible.
On this page you can learn more about the different forms of dementia, including both common and rarer forms.
How many types of dementia are there?
There are over 400 different types of dementia. Whilst dementia itself is not a disease, there are some diseases, such as Alzheimer’s, which cause it. Sometimes different types of dementia are present in a patient at the same time. When this happens, it is known as mixed dementia.
Common types of dementia
Most people diagnosed with dementia have one of 4 common types: Alzheimer’s Disease, Vascular Dementia, Frontotemporal Dementia and Dementia with Lewy Bodies. These types of dementia have slightly different symptoms and causes. You can find out more about each type below, and from our dedicated guides to each of these common types of dementia.
Alzheimer’s Disease is the most common type of dementia in the UK – making up about 2 in 3 diagnoses. It is caused by a speeding-up of normal ageing processes in the brain. Alzheimer’s does not have a single cause, but there are a number of factors that have been found to increase a person’s likelihood of developing it, including cardiovascular disease and family history. It is a degenerative condition; the symptoms become more severe over time.
This is the second most common type of dementia in older people. Vascular Dementia is caused by a lack of oxygen reaching cells in the brain, causing the cells to be damaged. This leads to reduced brain activity. The most common symptom of Vascular Dementia is a significant slowness of thought, and it is a degenerative condition – it gets worse as time goes on. For this reason, many people with Vascular Dementia require round-the-clock care
Read more about the causes, symptoms and treatments for Vascular Dementia in our Vascular Dementia Guide.
Frontotemporal Dementia (FTD) is less common than Alzheimer’s and Vascular Dementia, but is actually the 3rd most common type of dementia for people aged under 65. The damage to the brain cells affects the frontal and temporal lobes of the brain. These are the areas of the brain related to problem-solving, behaviour and recognition – and so people with frontotemporal dementia tend to struggle with these things.
Read more about what causes frontotemporal dementia, common symptoms and available treatments in our Guide to Frontotemporal Dementia.
You may have heard Frontotemporal Dementia referred to as Pick's Disease — they are the same thing.
Dementia with Lewy Bodies
Dementia with Lewy Bodies (DLB) is another common form of dementia. It is caused by a build up of proteins called Lewy Bodies in the body. Lewy Bodies are also what cause Parkinson’s disease, which is why both illnesses share the symptoms of reduced mobility and a ‘shuffling’ walk. DLB also causes significant mental decline associated with the other major types of dementia, including lapses in memory and forgetfulness.
Read more about Dementia with Lewy bodies, including symptoms and treatments, in our Guide to Lewy Body Dementia.
Less common types of dementia
Though they are much more rare, there are other types of dementia. 5% of all dementia cases in the UK are caused by rarer forms of dementia. It is thought that most forms of rare dementia are under-diagnosed – in part because people do not know to look out for them. Some rarer forms of dementia have very specific symptoms that differ from other types of dementia.
Below you can find out more about rare types of dementia:
Korsakoff Syndrome is a rare form of progressive dementia which is caused by a deficiency of Vitamin B-1. People with Korsakoff Syndrome tend to struggle to retain new information, and may have long-term memory gaps. Their social and thinking skills tend to remain unaffected in spite of this.
It is most commonly found in people who have a history of alcohol misuse. It can also be caused by other conditions such as cancer, AIDS, or poor nutrition.
Progressive Supranuclear Palsy
Progressive Supranuclear Palsy (PNP) is a type of rare dementia which leads to difficulties with balance, mobility, swallowing, language and vision. As a progressive form of dementia, the symptoms become worse over time.
PNP is caused by damage to brain cells because of the protein ‘tau’ building up in the brain.
Corticobasal Degeneration (CBD) is a rare type of dementia that is most often found in people aged 50 to 70. The symptoms of CBD include difficulty balancing, tremors, muscle stiffness and difficulty controlling a limb on one side of the body e.g. not being able to voluntarily move a hand.
CBD is also caused by damage to brain cells due to the build up of a protein called 'tau'.
Huntington’s disease is a rare inherited condition that causes dementia. It tends to be diagnosed in people aged 30 - 45, and the first symptoms are usually difficulty with movement. Other symptoms include memory lapses, difficult swallowing, and severe mood swings.
Huntington’s disease dementia is caused by a faulty gene that leads to gradual damage to the brain.
Niemann-Pick Disease Type C
Niemann-Pick Disease Type C is a condition that can lead to dementia, particularly in people who are diagnosed in childhood, adolescence or early adulthood. People are usually diagnosed with Niemann-Pick disease type C dementia after showing symptoms of poor memory, poor concentration and communication difficulty.
Niemann-Pick disease is caused by an inherited inability to break down fats, which causes the fats to accumulate in cells - including those in the brain.
Normal Presure Hydrocephalus
Normal Pressure Hydrocephalus (NPH) is a rare type of dementia that is found mainly in older people. The hallmarks of NPH are decline in processing speed, forgetfulness, and an unusual walking style as though a person was “on a boat”: with feet spread wide, and body bent forward. As the condition deteriorates, urinary incontinence is another common symptom.
Normal Pressure Hydrocephalus is caused by an excess of cerebrospinal fluid in the brain.
Parkinson's Disease Dementia
Parkinson’s Disease Dementia is a rare form of dementia that occurs in people with Parkinson’s Disease. Parkinson’s Disease is caused by Lewy Bodies in the brain – which affect the parts of the brain that are responsible for movement. As the condition develops, however, the changes to the brain caused by the Lewy Bodies start to affect parts of the brain linked to memory, concentration and the ability to think through tasks.
Posterior Cortical Atrophy
Posterior Cortical Atrophy (PCA) is a type of dementia that shares a lot of similarities with Alzheimer’s Disease (link) but occurs in a different part of the brain: the cortex (outer layer). It most commonly is diagnosed in people aged 50 to 65. The symptoms vary a lot from person to person, but it is common for a person with PCA to struggle to process visual information e.g. reading, estimating distances, handling objects.
Creutzfeldt-Jakob Disease (CJD) is a prion disease that causes a type of dementia that gets worse unusually fast. Common symptoms of Creutzfeldt-Jakob Disease are problems with memory, mood swings and low mood, confusion, and muscle stiffness.
Prion diseases cause proteins in the body to fold into abnormal shapes. In this case of CJD, misfolded proteins in the brain cause damage to the function of brain cells.