Alzheimer's is a degenerative brain disease that usually begins gradually, causing a person to forget recent events or familiar tasks. How rapidly it advances varies from person to person, but the disease eventually leads to confusion, personality and behavior changes and impaired judgment. Communication becomes more difficult as the disease progresses, leaving those affected struggling to find words, finish thoughts or follow directions. Eventually, most people with Alzheimer’s disease become unable to care for themselves.

One in 10 people over 65 and nearly half of those over 85 suffer from Alzheimer’s disease. Today, 4 million Americans have the condition. That number could jump to 14 million by the year 2050 unless prevention methods are developed.

Scientists still are not certain of the disease's cause. Advancing age and family history are risk factors. Researchers are exploring the role of genetics in the disease, but most agree it's caused by a variety of factors.

There is no single, comprehensive diagnostic test for Alzheimer’s disease. Instead, doctors rule out other conditions through a process of elimination. They usually conduct physical, psychological and neurological exams and take a thorough medical history. Diagnosis is about 90 percent accurate, but the only way to confirm it is through autopsy.

There is no medical treatment currently available to cure or stop the progression of Alzheimer's disease. There are currently four FDA-approved Alzheimer's drugs -- Cognex, Aricept, Exelon and Reminyl -- that may temporarily relieve some symptoms of the disease. Several other drugs are in development.

Common symptoms of Alzheimer's disease include:

• Memory loss that affects job skills
• Difficulty performing familiar tasks
• Problems with language
• Disorientation to time and place
• Poor or decreased judgment
• Problems with abstract thinking
• Placing items in inappropriate places
• Rapid changes in mood or behavior
• Dramatic changes in personality
• Loss of initiative