In the clinic, cerebrospinal fluid biomarkers can be used to help diagnose Alzheimer’s or other types of dementia. Biomarkers of amyloid plaque burden (A), tau neurofibrillary tangles (T), and neurodegeneration (N) can be measured in cerebrospinal fluid to aid in diagnosis of Alzheimer’s disease. In research, other cerebrospinal fluid biomarkers might be valuable tools for early detection of a neurodegenerative diseases, such as Alzheimer’s, as well as to assess the impact of medications in clinical trials. Also, more recently, proteins in the blood have been discovered that can alert the clinician and patient to the possibility of Alzheimer’s disease. This is useful for referral of the patient to a specialist for diagnosis.