Alzheimer's disease is the most common form of dementia. It is a neurodegenerative disease that causes deterioration of the brain and destruction of nerve cells. This leads to a loss of functioning in the brain and difficulties sending proper signals. While the cause is unknown, family history increases risk. Alzheimer's affects the brain, causing shrinkage and clumps/tangles that impair intellectual functioning. Symptoms worsen over 7 stages, from mild memory loss to severe impairment. Currently there is no cure, but drugs can help treat some symptoms.