Doctors use methods such as a physical examination, laboratory tests, an inventory of related symptoms and a medical history to diagnose dementia according to the Alzheimer's Association. They may also conduct a neurological exam and mental status tests.
During a diagnostic medical workup, the doctor may ask the patient about his diet, symptoms and medications as well as perform routine procedures such as a blood pressure check, as stated by the Alzheimer's Association. He may also collect urine and blood samples to rule out other possible conditions. During the neurological exam, the doctor tests reflexes, eye movement, speech and coordination to check for problems that may signal other brain disorders.
The doctor may conduct a number of mental status tests including a mini mental state exam, a mini-cog test and a mood evaluation, as listed by the Alzheimer's Association. These tests are designed to determine whether the patient knows the time and date, is aware of symptoms, understands the surrounding environment and can remember short lists of words. Although doctors can discover whether or not a patient has dementia with relative certainty, diagnosing the exact type of dementia is more difficult due to an overlap of symptoms. The Alzheimer's Association advises against home screening tests for self-diagnosis of dementia as they cannot replace a thorough examination by a trained medical professional.