Spotlight on Alzheimer's Disease - U.S. News & World Report (usnews.com).
Alzheimer's disease is a progressive disease that damages nerve cells (neurons) in parts of the brain involved in memory, learning, language, and reasoning. As the disease progresses, communication among the neurons breaks down. In early stages, short-term memory begins to fail. Over time, functions such as long-term memory, language, and judgment decline. Alzheimer's disease is the most common cause of dementia in older adults. Dementia is a loss of mental functions-such as thinking, memory, and reasoning-that is severe enough to interfere with a person's daily functioning.