Alzheimer's, AWLTS hy muhrz, disease, often abbreviated as AD, is the most common cause of dementia late in life. Dementia is characterized by loss of the ability to think clearly. People with AD may forget names, conversations, or recent events. As the disease progresses, memory loss increases, and patients begin to lose other mental functions. Patients can become confused or disoriented, easily getting lost even in familiar locations. In later stages, patients lose the ability to remember or talk meaningfully. Eventually, they cannot care for themselves and become bedridden, requiring constant care. In their weakened condition, patients are vulnerable to pneumonia and other infectious diseases. Most patients die from such infections 10 to 12 years after developing AD.