Dementia is caused by damage to brain cells. This damage interferes with the ability of brain cells to communicate with each other and affecting one’s thinking, behavior and feelings. The two most common types are Alzheimer's disease and vascular 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 which result in one having difficulty to function a normal life.
Vascular dementia is caused by reduced blood flow to the brain. To function properly, brain cells need a constant supply of blood to bring oxygen and nutrients. If the vascular system within the brain becomes damaged, blood cannot reach the brain cells and they will eventually die. This will then result in problems with memory, thinking or reasoning.