Alzheimer's disease is a progressive neurological disease of the brain leading to the irreversible loss of neurons and the loss of intellectual abilities, including memory and reasoning. The disease is caused by a build-up of proteins in the brain. The buildup occurs in two main ways, Plaques and tangles. Plaques are deposits of the protein beta-amyloid that accumulate in the spaces between nerve cells and tangles are deposits of the protein tau that accumulate inside of nerve cells. Scientists are still studying how plaques and tangles are related to Alzheimer's disease. One theory is that they block nerve cells' ability to communicate with each other, making it difficult for the cells to survive.
A more intricate explanation about how the disease occurs can be seen in this video:
Treatment for Alzheimer's usually involves the use of Cholinesterase inhibitors. These inhibitors curb the breakdown of acetylcholine, a chemical in the brain important for memory and learning. These types of medications help increase the levels of acetylcholine in the brain, thus help with memory retention.
People with Alzheimer's experience the disease in 3 main phases. In the first phase of the disease the patient is noticeably slower with brain functions and begins having trouble with memory. The second stage is similar to the first and usually accompanied by a behavioral change. And the final stage is most noticeable as the patients abilities severely decline and a move into a nursing home may be necessary.
Alzheimer's is an unfortunate disease and can be one of the hardest for family members to deal with because their loved one simply cannot remember them.