Stroke Warning Signs and Risk Assessment
Learn to recognize stroke symptoms using the FAST method, understand risk factors, and discover how clinical tools assess stroke severity and TIA risk.
What Is a Stroke?
A stroke occurs when blood supply to part of the brain is interrupted or severely reduced, depriving brain tissue of oxygen and nutrients. There are two main types: ischemic stroke, caused by a blood clot blocking a brain artery (accounting for about 87% of all strokes), and hemorrhagic stroke, caused by a blood vessel rupturing and bleeding into the brain. A transient ischemic attack (TIA), often called a 'mini-stroke,' produces similar symptoms that resolve within 24 hours but signals a significantly increased risk of a full stroke in the near future.
Recognizing Stroke: The FAST Method
The FAST acronym is the most widely promoted tool for rapid stroke recognition. F (Face): Ask the person to smile — does one side of the face droop? A (Arms): Ask the person to raise both arms — does one arm drift downward? S (Speech): Ask the person to repeat a simple sentence — is their speech slurred or strange? T (Time): If you observe any of these signs, call emergency services immediately. Time is critical in stroke treatment — every minute of delayed treatment results in the loss of approximately 1.9 million neurons.
Other Warning Signs
Beyond the FAST symptoms, other stroke warning signs include sudden severe headache with no known cause, sudden confusion or difficulty understanding speech, sudden trouble seeing in one or both eyes, sudden dizziness, loss of balance, or difficulty walking, and sudden numbness or weakness — especially on one side of the body. These symptoms typically appear without warning and can occur alone or in combination. Any sudden neurological symptom should be treated as a potential stroke until proven otherwise.
Stroke Risk Factors
Modifiable risk factors for stroke include high blood pressure (the single most important modifiable risk factor), atrial fibrillation, diabetes, high cholesterol, smoking, physical inactivity, obesity, and excessive alcohol use. Non-modifiable risk factors include age (risk doubles each decade after age 55), sex (men have higher risk, but women have higher mortality), family history, and prior stroke or TIA. Managing modifiable risk factors through lifestyle changes and medication can significantly reduce stroke risk.
Clinical Assessment Tools
Healthcare providers use standardized scoring systems to assess stroke severity and predict outcomes. The NIH Stroke Scale (NIHSS) evaluates 11 aspects of neurological function — including consciousness, vision, motor strength, sensation, and language — to quantify stroke severity on a scale from 0 to 42. The ABCD2 score predicts the short-term risk of stroke following a TIA by scoring age, blood pressure, clinical features, duration of symptoms, and presence of diabetes. These tools help guide treatment urgency and resource allocation.
Disclaimer: This tool is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with questions about your health.
Related Tools
NIH Stroke Scale
Calculate the NIH Stroke Scale score to quantify stroke severity. Used to guide acute stroke treatment decisions including thrombolysis.
ABCD² Score
Calculate the ABCD² score to estimate the short-term risk of stroke following a transient ischemic attack (TIA).
Glasgow Coma Scale
Calculate the Glasgow Coma Scale score to assess level of consciousness. Used worldwide in emergency medicine and trauma assessment.