The purpose of the Dizziness Diagnostic Tool is to provide a point-of-care resource for clinicians diagnosing dizzy patients. Dizziness is the third most common symptom of patients presenting to general medical clinics. Acute vestibular syndrome is one type of dizziness characterized by a sudden onset, persists for a day or more, and is accompanied by nausea or vomiting, poor balance, and intolerance to head motion. Each year, half a million people present to the ED with acute vestibular syndrome. It is most often caused by viral infection in which case it is not dangerous. However, roughly 25% of strokes, a much more dangerous cause, can look exactly like such a viral infection. As a result, just under half of these strokes are initially missed by clinicians putting twenty thousand patients a year at significant risk for disability and death. Physicians need tools to help sort out when dizziness requires more careful follow-up and when patients can be sent home. That is where the Dizziness Diagnostic Tool can help. The diagnostic tool guides physicians through the relevant parts of the patient history and physical exam and uses Bayesian statistics to calculate how probable it is that the patient had a stroke based on the collected data. It is our hope that such a tool may aid in diagnosis and improve outcomes among patients presenting with this common problem. Please refer to this document for more information.