Dementia is a syndrome that is associated with an ongoing decline of the brain and its abilities. These includes memory, thinking, language, understanding and judgement. People with dementia may also become apathetic, have problems controlling their emotions or behaving appropriately in social situations. Aspects of their personality may change or they may see or hear things that other people do not, or have false beliefs. Most cases of dementia are caused by damage to the structure of the brain. People with dementia usually need help from friends or relatives, including help in making decisions.

Dementia or dementia-like symptoms can have a number of less common causes, some of which are treatable that includes: repeated injury to the head, infections of the brain, such as meningitis or encephalitis, Huntington’s disease, a rare genetic condition that causes progressive brain damage, Creutzfeldt-Jakob disease (CJD), a rare and fatal condition that causes damage to the brain and nervous system
an overactive or underactive thyroid gland, dehydration, lack of vitamin B in the diet, poisoning, for example from lead or pesticides, having a brain tumour, certain lung and heart conditions that interrupt the supply of blood and oxygen to the brain.

There is no cure for dementia and symptoms will get worse over time. However, there are a number of effective treatments that can help people to cope better with their symptoms and improve their quality of life.