What is dementia?

Dementia is caused when the brain is damaged by diseases, such as Alzheimer’s disease or a series of strokes. Alzheimer’s disease is the most common cause of dementia, but not the only one. The specific symptoms that someone with dementia experiences will depend on the parts of the brain that are damaged and the disease that is causing the dementia. This factsheet explains what dementia is, including the causes and symptoms, and how it is diagnosed and treated. It also looks at some of the different types of dementia.


Each person will experience dementia in their own way. The different types of dementia tend to affect people differently, especially in the initial stages. Other factors that will affect how well someone can live with dementia include how other people respond to them and the environment around them.

A person with dementia will have cognitive symptoms (to do with thinking or memory). They will often have problems with some of the following:

  • Day-to-day memory – for example, difficulty recalling events that happened recently concentrating, planning or organising.
  • Language – for example, difficulties following a conversation or findinga right word.
  • Visuospatial skills – for example, problems judging distances (such as onstairs) and seeing objects in three dimensions.
  • Orientation – for example, losing track of the day or date, or becomingconfused about where they are.

What causes dementia?

There are many diseases that result in dementia. The most common types of dementia are outlined below:

  • Alzheimer’s disease : This is the most common cause of dementia. In Alzheimer’s disease, an abnormal protein surrounds brain cells and another protein damages their internal structure. In time, chemical connections between brain cells are lost and cells begin to die. Problems with day-to-day memory are often the first thing to be noticed, but other symptoms may include difficulties finding the right words, solving problems, making decisions, or perceiving things in three dimensions.
  • Vascular dementia:If the oxygen supply to the brain is reduced because of narrowing or blockage of blood vessels, some brain cells become damaged or die. This is what happens in vascular dementia. The symptoms can occur suddenly, following one large stroke. Or they can develop over time, because of a series of small strokes. Vascular dementia can also be caused by disease affecting the small blood vessels deep in the brain, known as subcortical.

The symptoms of vascular dementia vary and may overlap with those of Alzheimer’s disease. Many people have difficulties with problem-solving or planning, thinking quickly and concentrating. They may also have short periods when they get very confused.

  • Mixed dementia: This is when someone has more than one type of dementia, and a mixture of the symptoms of those types. It is common for someone to have both Alzheimer’s disease and vascular dementia together.
  • Dementia with Lewy bodies: This type of dementia involves tiny abnormal structures (Lewy bodies) forming inside brain cells. They disrupt the chemistry of the brain and lead to the death of brain cells. Early symptoms can include alertness that varies over the course of the day, hallucinations, and difficulties judging distances. A person’s day-to-day memory is usually affected less than in the early stages of Alzheimer’s disease. Dementia with Lewy bodies is closely related to Parkinson’s disease and often has some of the same symptoms, including difficulty with movement.
  • Frontotemporal dementia –:In frontotemporal dementia, the front and side parts of the brain are damaged. Clumps of abnormal proteins form inside brain cells, causing them to die. At first, changes in personality and behaviour may be the most obvious signs. Depending on which areas of the brain are damaged, the person may have difficulties with fluent speech or forget the meaning of words.

The symptoms of these types of dementia are often different in the early stages but become more similar in the later stages. This is because more of the brain is damaged as the different diseases progress. In the later stages of dementia, the person will need more and more support to carry out everyday tasks. However, many people with dementia live well for years after their diagnosis. Information, advice and support are available for the person and their carer to help them live well with dementia.

Rare causes of dementia:

There are many other diseases that can lead to dementia. These are rare – together they account for only about 5 percent of all dementia. They tend to be more common among younger people with dementia (under the age of 65).These rarer causes include corticobasal degeneration, progressive supranuclear palsy, HIV infection, Niemann-Pick disease type C, and Creutzfeldt-Jakob disease (CJD).

Some people with Parkinson’s disease or Huntington’s disease develop dementia as the illness gets worse. People with Down’s syndrome are also at a particular risk of developing Alzheimer’s disease as they get older. For more information see factsheet 442, Rarer causes of dementia.

  • Mild cognitive impairment: Some people have problems with their memory or thinking but these are not bad enough to affect their everyday life. In this case, a doctor may diagnose them with mild cognitive impairment (MCI). This is not a type of dementia, but research shows that people with MCI have an increased risk of going on to develop dementia. .

However, MCI can also be caused by other conditions such as anxiety, depression, physical illness and the side effects of medication. Because of this, some people with MCI do not go on to develop dementia, and a small number of people will even get better

How can I tell if I have dementia?

Becoming a little forgetful does not mean that you have dementia. Many people notice that their thinking gets a bit slower as they get older – for example, they might occasionally forget a friend’s name or a contact no. These symptoms can also be a sign of stress or certain physical illnesses.

However, anyone who is worried that their memory is getting noticeably worse, or who has other symptoms such as those listed above, should discuss with our Best Neurologist in Faridabad Now.

Diagnosing dementia:

Anyone who has problems with their memory or thinking to get a proper check-up. These problems may be caused by stress, or an infection, rather than dementia. Finding out the cause may allow the person to get the right treatment.

But, if these problems are because of dementia, getting a diagnosis has many benefits. It provides someone with an explanation for their symptoms, gives them access to treatment, advice and support, and allows them to prepare for the future and plan ahead. Knowing the type of dementia (for example, Alzheimer’s disease or vascular dementia) is also important, partly because it may allow the person to get an appropriate drug treatment.

How is dementia treated?

The vast majority of causes of dementia cannot be cured, although research is continuing into developing drugs, vaccines and other medical treatments. There is a lot that can be done to enable someone with dementia to live well with the condition. Care and support should be ‘person-centred’. This means it should be focused on person’s needs and preferences.

Non-drug treatments and support

Non-drug treatments include information, advice, support and therapies.

Support for the person and their carer should be available after a diagnosis. This should give them the chance to talk things over with a professional, ask questions about the diagnosis, and think about the future. It’s also important to get information on planning ahead, where to get help with this and how to stay well, both physically and mentally. Other types of treatment include the following:

Talking therapies, such as counselling, can help someone come to terms with their diagnosis or

discuss their feelings.

Cognitive behavioural therapy (CBT) may be offered if the person develops depression or anxiety.

Cognitive stimulation therapy is a popular way to help keep someone’s mind active. It involves doing themed activity sessions over several weeks.

Cognitive rehabilitation can help an individual to recall skills and handle better. There is also lots that can be done at home to help someone with dementia remain independent and live well with memory loss. Support ranges from devices such as pill boxes or calendar clocks to practical tips on how to develop routines or break tasks into simpler steps.

Can dementia be prevented?

It is not usually possible to say for sure why a particular person has developed dementia. Factors such as high BP, lack of exercise and smoking – all of which lead to narrowing of the arteries – increase the risk of developing Alzheimer’s disease and vascular dementia. There is evidence that a healthy lifestyle, especially in mid-life, can help reduce the risk of dementia. Regular physical exercise (for example, cycling, swimming, brisk walking), maintaining a healthy weight, not smoking, and drinking alcohol only in moderation, if at all, are linked to a reduced risk of dementia.

A healthy balanced diet also helps to reduce a person’s risk. A balanced diet is one which is low in saturated fat, does not have too much salt, sugar or red meat, and includes plenty of fish, starchy foods, and fruit and vegetables. All these healthy lifestyle choices will also reduce the risk of other serious conditions such as stroke, heart disease and cancer.

A person who is already living with conditions such as diabetes, heart problems, high blood pressure or high cholesterol should follow professional advice to keep their condition under control. Getting depression treated early is also important.

By being mentally and socially active may help lower a person’s risk of dementia. Being mentally active could include doing puzzles or reading, or learning a new skill. Being socially active could include visiting friends or going to a place of worship. Volunteering could offer both mental and social activity and many organisations offer opportunities for people looking to donate their time or skills.