There is currently no single test that can tell if a person has Alzheimer's disease. AD is definitively diagnosed only after death by an autopsy examination of brain tissue.  But doctors now have several methods and tools to help them determine fairly accurately whether a person who is having memory problems is experience "possible AD" or "probable AD". The diagnosis can be made in a family doctor's office, a memory clinic or a hospital. 

Doctors user a systematic assessment which eliminates other possible causes in order to arrive at a diagnostic conclusion. It's possible that your doctor will ask for the help of a psychologist, psychiatrist, neurologist, geriatrician, nurse, social worker or occupational therapist. These mental health professionals will look for problems with memory, reasoning ability, language and judgment, and how these affect day-to-day function.

To diagnose Alzheimer disease, doctors use the following protocol:

1. Medical history - Ask questions about the person's overall health, past medical problems, ability to carry out daily activities, and changes in behavior and personality
2. Mental status exam - Conduct tests of memory, problem solving, attention, counting, and language
3. Physical exam - The doctor will look for other problems that may be causing the symptoms. To evaluate whether other nervous system disorders are causing the symptoms, the doctor will test muscle tone and strength, co-ordination, eye movement, speech and sensation.
4. Laboratory tests - Carry out medical tests, such as tests of blood, urine, or spinal fluid
5. Imaging tests- Perform brain scans, such as a computerized tomography (CT) scan or a magnetic resonance imaging (MRI) test

These tests may be repeated to give doctors information about how the person's memory is changing over time. It's important to note that doctors making an AD diagnosis are accurate 80 to 90 per cent of the time and a full diagnosis can take time. You can prepare for a diagnostic appointment by reading and recording the following information for your doctor.

• What symptoms have you noticed?
• When did they first appear?
• How have the symptoms changed over time?
• What other medical conditions exist?
• What medications are you taking (prescription and over-the-counter)?
• What herbal remedies and/or dietary supplements are you taking?
• Is there a family history of Alzheimer's disease or psychiatric conditions?

Although we still don't know what starts the AD process, we do know that damage to the brain begins as many as 10 to 20 years before any problems are evident.   Consult a doctor when you have concerns about memory loss, thinking skills and behavior changes in yourself or a loved one.  It is important for a doctor to determine the cause of memory loss or other symptoms.  Continue reading to learn more about how to treat dementia and Alzheimer's symptoms.