What Causes Alzheimer's Disease?

Alzheimer’s disease develops due to a combination of biological, genetic, and lifestyle factors that gradually damage brain cells over time. Although researchers have learned a great deal about the disease, there is still no single cause that explains every case.
The cause of Alzheimer’s is not yet well understood. However, researchers have found buildup of beta-amyloid plaques outside brain cells and tau protein tangles inside neurons as responsible causes. These abnormal protein deposits interfere with communication between nerve cells, disrupt essential cellular functions, and eventually lead to the death of neurons. As more brain cells are lost, areas responsible for memory, reasoning, and behavior begin to shrink.