Exams and Tests

Alzheimer's disease is diagnosed after other conditions are ruled out. If you are suffering from a decline in mental abilities (dementia), your doctor will try to find out if another treatable condition may be causing those symptoms.

• It is very important to rule out delirium as a possible cause of symptoms, especially if the symptoms came on suddenly rather than gradually. Delirium may require emergency medical attention.
• Symptoms of confusion and memory loss can sometimes be caused by depression. Depression is very common among older adults, but it is sometimes difficult to recognize. It may be successfully managed with medicine and counseling.

Alzheimer's disease is diagnosed with a medical history and a physical exam. A physical exam is used to help find out if a physical problem may be causing a person's dementia symptoms. It may be possible to correct some of these problems. For example, sometimes a simple hearing or vision problem can cause confusion, social withdrawal, or a change in behavior, such as hostility or unresponsiveness. The person may have an undiagnosed illness or infection that is causing the symptoms.

Also, the doctor will do a functional status exam and a mental health assessment. During these exams, the person will be asked to perform simple tasks that check orientation. It usually is helpful to have a family member or someone in close contact with the person present at the appointment. A family member may be able to provide the best information about how a person's day-to-day functioning, memory, and personality have changed.

Brain imaging tests such as CT scans and magnetic resonance imaging (MRI) may also be done to make sure another problem is not causing the symptoms. Your doctor may also test for certain proteins in your spinal fluid to rule out other causes. Positron emission tomography (PET) or single photon emission tomography (SPECT), two other imaging tests, are not routinely done but may be useful in some cases.

Lab tests

A small number of people with dementia have a condition that proper treatment can reverse (unlike Alzheimer's disease). Lab tests may be done to rule out other possible causes of a person's symptoms, such as levels of certain minerals or chemicals in the blood that are too high or too low, liver disease, abnormal thyroid levels, or nutritional problems, such as folate or vitamin B12 deficiencies. Treatment for these conditions may slow or reverse mental decline.