Dementia is tested through a combination of assessments because no single test can diagnose it definitively. The diagnostic process typically starts with taking a detailed personal and medical history, including symptom onset and impact on daily life, often with input from someone who knows the person well. Doctors then conduct cognitive tests to assess memory, thinking, reasoning, language, and other mental abilities. These tests include tools like the Mini- Mental State Examination (MMSE), General Practitioner Assessment of Cognition (GPCOG), and the Montreal Cognitive Assessment (MoCA). There are also longer, specialized neuropsychological tests done by specialists to measure cognitive skills more deeply. Neurological exams test physical functions like balance, reflexes, coordination, and eye movement to see how well the brain and nervous system are working. Blood tests are important to rule out other causes of symptoms, such as vitamin deficiencies or thyroid problems, and sometimes special blood tests look for proteins linked to Alzheimer's disease. Brain imaging scans (CT, MRI, PET) are used to look for structural or functional brain changes, such as tumors, strokes, or amyloid plaques related to Alzheimer's. Finally, a psychiatric evaluation may be done to check for mental health conditions like depression that could affect cognition. In sum, dementia diagnosis is a multi-step process involving history, cognitive tests, neurological exams, lab tests, brain scans, and psychiatric assessment to accurately identify the condition and rule out others.