Alzheimer's disease is a progressive and debilitating disease that robs those affected of their abilities to communicate, think clearly, function independently, and remember friends and family. It is caused by plaques and tangles forming in the brain that damage and kill neurons. There is no known cure, but some treatments can help slow progression. Prevention through lifestyle factors like exercise, diet, and mental stimulation may reduce risk. Alzheimer's places a large emotional and financial burden on patients and their families.