Dementia is a mental disorder characterized by impairment of general intellectual disfungcioning, often with impaired memory, difficulty in counting, confusion, changes of mood and emotions, impaired judgment, and abstraction, reduced verbalabilities and disturbed orientation. Dementia is a progressive disease that causes loss of mental ability, which results in personality changes, memory loss and social skills. It is not a normal part of aging and most people never develop. The main symptom is forgetfulnes, and there are seven stages of the disease, the mildest to the most difficult. It occurs in several clinical forms of dementia and each has its cause. The basis of all is importance the symptoms and therapy to take patient candelay terminal phase of the disease, so they can maintain a greater degree of independence. In addition to pharmacologic therapy in dementia, there are new innovative discoveries that have contributed being longer patients home with his family, and to avoid the potential dangers of the disease with them. The main cause of the dangeuros is the main symptom of the disease, forgetfulness. There are also measures to be implemented in the prevention of dementia. There is a lot of work on proper nutrition, with a population that has no symptoms and adequate physical activity. People need to treat any organic disease that can lead to the development dementia. It si very important to educated healthy and diseased populations healthy in order to prevent the occurrence of disease and also the ill population to learn to live with the disease and maintain the highest possible degree of independence as long as possible.