What happens in the brain?

The nerve cells in the brain break down. Sometimes the nerve cells themselves do not break, but the connections between the cells. It is also possible that the cells and the connections are no longer doing well.

Because of this decrease of cells, the brain functions less and less well. In some people, the decline is very fast. Others can lead a reasonably normal life for years to come. Eventually someone gets very weakened by the effects of dementia. The person then dies due to a disease or infection (eg pneumonia) or because he can no longer swallow.