Alzheimers's Disease

Symptoms
Memory loss is usually the first sign of Alzheimer's disease. Many older people may worry about Alzheimer's disease if they start to have memory problems. Having some short-term memory loss in your 60s and 70s is common, and some people with mild memory problems will go on to develop Alzheimer's disease. If you start having memory problems, share your concerns with your family and your doctor.

Examples of normal forgetfulness include forgetting:
Parts of an experience.
Where the car is parked.
Events from the distant past.
A person's name, remembering it later.
Where you left an object, such as your car keys.

Examples of memory loss caused by Alzheimer's disease include forgetting:
An entire experience.
How to drive a car or read a clock.
Recent events, such as forgetting you left the stove on.
Ever having known a particular person.
Alzheimer's disease also causes changes in thinking, behavior, and personality. Early in the disease, the person may still behave appropriately in social situations, leading others to believe that the person is not ill. Close family members and friends may first notice the symptoms of Alzheimer's disease, although the person may also realize that something is wrong.

Learn the warning signs of dementia—such as having difficulty thinking or remembering, or having trouble balancing a checkbook—and talk to a doctor if a friend or family member has developed any of the signs. Symptoms vary as the disease progresses.

More...
http://health.yahoo.com/alzheimers-symptoms/alzheimer-s-disease-symptoms/healthwise--hw136643.html