Vascular dementia is caused by reduced blood supply to the brain due to diseased blood vessels.
To be healthy and function properly, brain cells need a constant supply of blood to bring oxygen and nutrients. Blood is delivered to the brain through a network of vessels called the vascular system. If the vascular system within the brain becomes damaged - so that the blood vessels leak or become blocked - then blood cannot reach the brain cells and they will eventually die.
This death of brain cells can cause problems with memory, thinking or reasoning. Together these three elements are known as cognition. When these cognitive problems are bad enough to have a significant impact on daily life, this is known as vascular dementia.