Alzheimer's disease (AD) is not a normal part of aging.  Instead, brain changes occur in people with Alzheimer's disease. Those diagnosed with AD lose nerve cells and pathways in areas of the brain that are vital to memory and other mental abilities. Specifically, "plaques" and "tangles" form in particular brain areas, healthy neurons begin to work less efficiently and eventually they die.  As the death of neurons increases, affected brain regions begin to shrink. By the final stage of AD, damage is widespread and brain tissue has shrunk significantly.

Alzheimer's disease is the most common form of dementia among older people.  AD is responsible for memory loss and loss of other intellectual abilities serious enough to interfere with daily life.   

Alzheimer's disease is both a progressive and fatal brain disease.  AD begins slowly. It first involves the parts of the brain that control thought, memory and language.  Over time, symptoms get worse.  Alzheimer's destroys brain cells, causing problems with memory, thinking and behavior severe enough to affect work, lifelong hobbies or social life. Eventually, someone diagnosed with Alzheimers needs total care as the disease is fatal.

As many as 5 million Americans are currently living with Alzheimer's disease; it is the sixth-leading cause of death in the United States. The disease usually begins after age 65 and risk goes up with age. While younger people also may get Alzheimer's disease, it is much less common.  To learn more about the signs and symptoms of Alzheimer's disease, continue reading here.