Dementia is a complex condition that is usually associated with the progressive loss of cognitive abilities and memory impairment. It is a chronic disease of the brain that can occur in various forms and degrees of severity. The consequences of dementia can affect many areas of daily life and therefore often have a major impact on the quality of life of the person affected as well as their family and friends. Dementia is not a disease in its own right, but rather a collective term for a number of diseases that are all associated with a reduction in cognitive abilities. The best-known forms of dementia include Alzheimer's disease, vascular dementia and Lewy body dementia. However, there are many other forms of dementia that differ in their causes, progression and symptoms