How to Recognize Signs of a Stroke and Act FAST

Stroke is the fifth leading cause of death in the United States and the leading cause of long-term disability. Each year, approximately 795,000 Americans experience a new or recurrent stroke. As with heart attacks, time is the critical variable — every minute of stroke without treatment results in approximately 1.9 million neurons lost. Modern treatments for ischemic stroke (the most common type) — clot-busting medication (tPA) and mechanical thrombectomy (clot retrieval) — can dramatically improve outcomes, but only if administered within specific time windows that begin the moment symptoms start.

Understanding how to recognize stroke symptoms and what to do when they occur can save a life or prevent permanent disability.

What Happens During A Stroke

An ischemic stroke — accounting for approximately 87% of all strokes — occurs when a blood vessel supplying the brain is suddenly blocked, cutting off blood flow to the downstream brain tissue. Without oxygen and glucose, neurons begin dying within minutes. The brain areas affected determines the type of neurological deficits — speech, vision, motor function, balance — depending on which blood vessel is blocked.

A hemorrhagic stroke — approximately 13% of strokes — occurs when a blood vessel ruptures, causing bleeding that damages brain tissue directly and raises intracranial pressure.

Recognizing Stroke: The Be-Fast Tool

Two well-established mnemonics help the public and responders recognize stroke symptoms:

FAST (older, widely taught):

• Face drooping (one side)
• Arm weakness
• Speech difficulty
• Time to call 911

BE-FAST (current recommendation — captures more stroke symptoms):

• Balance: Sudden loss of balance or coordination
• Eyes: Sudden vision changes (double vision, loss of vision in one or both eyes)
• Face: Facial drooping (asymmetric smile)
• Arms: Arm weakness (one arm drifts down)
• Speech: Slurred speech, wrong words, unable to speak or understand
• Time: Call 911 immediately; note the time symptoms started

Individual Symptoms In Detail

Face Drooping

Ask the person to smile. Is one side drooping? Does their face look asymmetric? Facial weakness from a stroke is typically on one side — resulting from damage to the opposite hemisphere's motor cortex. Bell's palsy (peripheral facial nerve palsy) also causes facial weakness but typically involves the forehead, differs in distribution, and usually is not accompanied by other stroke symptoms.

Arm Weakness

Ask the person to close their eyes and hold both arms out in front of them, palms up, for 10 seconds. Does one arm drift downward? Arm weakness in stroke is typically unilateral — one side of the body. Both arms lifting normally is reassuring; one drifting down is a positive sign.

Speech Changes

Aphasia: Difficulty with language — producing words (expressive aphasia: knows what they want to say but can't get the words out), understanding spoken language (receptive aphasia: doesn't understand what you're saying), or finding the right words.

Dysarthria: Slurred or garbled speech — the words are correct but pronunciation is impaired (from weakness of the speech muscles).

To test: Ask a simple question ("What's your name?"), ask them to repeat a simple sentence ("You can't teach an old dog new tricks"), or ask them to name familiar objects.

Vision Changes

Sudden vision problems affecting one or both eyes: Loss of vision in one eye (monocular blindness — may represent retinal artery occlusion or TIA), visual field cuts (loss of one half or one quarter of the visual field in both eyes), double vision, or visual neglect (ignoring one side of the visual field). Ask: "Do you have sudden trouble seeing?"

Balance And Coordination

Sudden vertigo (severe room spinning), imbalance, inability to walk normally, incoordination — particularly with weakness or other stroke symptoms. Cerebellar strokes manifest prominently with balance and coordination problems.

Severe Sudden Headache

The "thunderclap" headache — sudden onset, maximum intensity within seconds ("the worst headache of my life") — is the classic presentation of subarachnoid hemorrhage (bleeding around the brain from a ruptured aneurysm). This requires emergency care even without other neurological symptoms.

What To Do

1. NOTE THE EXACT TIME SYMPTOMS STARTED

This is critical: The time of stroke onset determines eligibility for tPA (within 4.5 hours) and thrombectomy (within 24 hours in selected patients). If someone woke with stroke symptoms, the time of last known normal (when they were last observed to be symptom-free) becomes the onset time.

1. CALL 911 IMMEDIATELY

Do not drive the person to the hospital yourself — EMS can perform an assessment, alert the stroke team at the receiving hospital (activating the "stroke code"), and route directly to a comprehensive stroke center if needed.

1. DO NOT GIVE FOOD, WATER, OR ASPIRIN

Stroke can impair swallowing — aspiration is a serious risk. Aspirin can worsen a hemorrhagic stroke. Neither should be given until a CT scan has ruled out hemorrhage.

1. MONITOR AND COMFORT

Stay with the person; keep them calm. If they lose consciousness: maintain airway, call 911 if not done, and be prepared to start CPR.

1. GATHER INFORMATION FOR EMS

Medications (particularly blood thinners — warfarin, DOACs), medical history, time of last normal, allergies.

Transient Ischemic Attack (Tia): The Warning Stroke

A TIA produces identical stroke symptoms that resolve completely — typically within an hour. It must be treated as a medical emergency: approximately 10–15% of TIA patients have a stroke within 90 days, with the highest risk in the first 48 hours.

Any stroke-like symptoms — even if they resolve — require emergency evaluation. Do not "wait and see."

Stroke Treatment

Ischemic stroke: tPA (alteplase/tenecteplase) within 4.5 hours of onset; mechanical thrombectomy (catheter-based clot retrieval) for large vessel occlusion within 24 hours. Both require hospital evaluation, CT imaging, and specialist involvement — which is why calling 911 immediately is essential.

Hemorrhagic stroke: Reversal of anticoagulation, blood pressure management, sometimes surgical intervention. No clot-busting drugs.