Alzheimer's Disease - Diagnosis

Diagnosis of AD is difficult. Its symptoms are similar to those of other diseases and to those of the normal aging process. For example, loss of memory and depression (see depressive disorder entry) are symptoms of AD, but they are also typical changes that take place as a person gets older.

The only way to be absolutely sure that a person has AD is to perform an autopsy of the brain after death. The autopsy will reveal tangles and plaques that characterize AD. But this method of diagnosis is of no value to a living person.

The main approach used in diagnosing AD is to rule out other disease possibilities. To do so, a doctor uses three methods: physical examination, medical history, and a variety of tests. A physical examination is used to make sure the patient is not suffering from some other medical problem, such as an infection or a mild stroke (see stroke entry). A medical history reveals changes in the patient's behavior. It also includes questions about drugs the patient is taking and other factors that may account for AD-like symptoms. Blood and urine tests, brain scans, and other tests are used to find out if other medical conditions exist that are causing the patient's abnormal behavior.