Dementia: symptoms, types, causes, diagnosis and treatment

The NHS says dementia is not only about memory loss. It can also affect the way you speak, think, feel and behave. Different types of dementia can affect people differently, and everyone will experience symptoms in their own way.

The NHS lists common early symptoms that may appear some time before a diagnosis. They are often mild and may get worse only very gradually. Family and friends may not notice or take them seriously for some time.

• Memory loss.

• Difficulty concentrating.

• Finding it hard to carry out familiar daily tasks, such as getting confused over the correct change when shopping.

• Struggling to follow a conversation or find the right word.

• Being confused about time and place.

• Mood changes.

The NHS says people often get confused about the difference between Alzheimer's disease and dementia. Dementia is the umbrella term for the symptoms. Alzheimer's disease is a type of dementia, and together with vascular dementia makes up the majority of cases.

The NHS says there are many different causes and types of dementia and that dementia is not a disease in itself. It results from damage to the brain caused by different diseases such as Alzheimer's, and the symptoms vary according to the part of the brain that is damaged.

The NHS says it is normal for your memory to be affected by stress, tiredness, certain illnesses and medicines, but if you are becoming increasingly forgetful, particularly if you are over the age of 65, it is a good idea to talk to a GP about the early signs of dementia.

The NHS and Alzheimer's Society describe several types. Some people have more than one type, which is called mixed dementia.

The NHS says that if you are worried about your memory, or think you may have dementia, it is a good idea to see a GP. If you are worried about someone else, encourage them to make an appointment and perhaps go with them. A GP will ask about your symptoms and other aspects of your health, and whether you are finding it difficult to manage everyday activities such as washing and dressing, cooking and shopping, and paying bills.

The NHS says memory problems do not necessarily mean you have dementia, and can have other causes such as depression and anxiety, sudden confusion (delirium) caused by a medical condition such as an infection, an underactive thyroid or side effects of some medicines. To help rule out other causes, the GP will do a physical examination and may organise a blood test and urine test, and you will be asked to do a memory or cognitive test.

If other causes are ruled out, the GP may refer you to a specialist such as an old-age psychiatrist, a geriatrician or a neurologist, who may work in a memory clinic. The specialist may organise more tests, including a brain scan such as a CT or MRI scan and further detailed memory tests. The NHS says most cases of dementia can be diagnosed after these assessments.

The NHS says there is currently no cure for dementia, but there are medicines and other treatments that can help with dementia symptoms. It says medicines for dementia symptoms are important but are only one part of care, and that other treatments, activities and support, including support for the carer, are just as important in helping people to live well with dementia.

The NHS says dementia is a term for symptoms that occur when there is a decline in brain function, and that many of the diseases that cause it are associated with an abnormal build-up of proteins in the brain, which causes nerve cells to function less well and ultimately die.

Alzheimer's Society says some things can increase your chances of developing dementia, including high blood pressure, physical inactivity, drinking too much alcohol, smoking, hearing loss and poor diet. Alzheimer's Society also says most types of dementia are not inherited from a parent to a child, while the NHS notes frontotemporal dementia is more likely to run in families than other common causes.

The NHS says the symptoms of dementia usually become worse over time. In the late stage, people will not be able to take care of themselves and may lose their ability to communicate. The NHS lists common symptoms of advanced dementia as severe memory problems, not recognising close family and friends, communication problems, mobility problems, behavioural and psychological symptoms such as agitation or wandering, bladder incontinence and difficulty eating and swallowing.

The pace of progression varies between people and between types, and the NHS pages do not give a single timescale. Speak to a GP, memory service or dementia nurse about what to expect in your own situation.

The NHS says mild cognitive impairment (MCI) is not a cause of dementia. It describes minor memory and thinking problems that are not severe enough to cause problems in everyday life. MCI can be caused by an underlying illness such as depression, anxiety or thyroid problems, and if the underlying illness is treated, symptoms often disappear.

In some people MCI symptoms will remain the same and not worsen, but the NHS says some people with MCI go on to develop dementia, usually caused by Alzheimer's disease.

The NHS says that with treatment and support many people are able to lead active, fulfilled lives with dementia. After diagnosis it says your doctor should talk to you and your family or carer about the type of dementia, how it might develop, treatments, a named professional to co-ordinate support, local care and support services, advocacy, driving and employment, and financial and legal advice, and should give you written information.

It says ongoing appointments are a chance to talk about plans for the future, such as a Lasting Power of Attorney or an advance statement about future care. The NHS also points to the Dementia Information Service and to Join Dementia Research for those who want to take part in research.

Alzheimer's Society lists poor diet among the things that can increase the chance of developing dementia. On supplements, the NHS says some people use remedies such as ginkgo biloba, curcumin or coconut oil, but there is not enough evidence to say whether such remedies are effective, so be wary of any products that claim to benefit people with dementia and consult a doctor first, since some remedies interact with prescribed medicines.

On the NHS, assessment starts with a GP, then referral to a memory service or specialist, where cognitive tests and scans are arranged. After diagnosis, the GP and memory service review your care and may jointly prescribe medicines.

Some people choose a private memory assessment or neurology or old-age psychiatry consultation for quicker access. Whichever route you take, it helps to have someone who knows you well attend, to ask for written information, and to make sure the GP is informed so that support and reviews continue.