Stroke is the second leading cause of death and the third leading cause of disability globally, with approximately 15 million strokes occurring each year. It is a medical emergency with a narrow treatment window: for ischaemic stroke (caused by arterial blockage), each minute without treatment results in the loss of approximately 1.9 million neurons. The phrase "time is brain" captures why recognising stroke symptoms and calling emergency services immediately — before attempting to verify or "wait and see" — is the single most impactful action a bystander can take.
Recognising Stroke: The FAST Acronym
The FAST acronym remains the most widely validated public awareness tool for stroke recognition: F — Face drooping: one side of the face droops or is numb; ask the person to smile and observe for asymmetry. A — Arm weakness: one arm is weak or numb; ask the person to raise both arms and observe if one drifts downward. S — Speech difficulty: slurred, garbled, or absent speech, or difficulty understanding language. T — Time to call emergency services: if any of these signs are present, call immediately. An expanded version — BE-FAST — adds Balance problems and Eyes (sudden vision change or loss) to improve sensitivity. These symptoms warrant immediate emergency response even if they resolve quickly — a transient ischaemic attack (TIA, "mini-stroke") carries a 10% risk of completed stroke within 48 hours.
Types of Stroke and Risk Factors
Approximately 87% of strokes are ischaemic — caused by thrombosis or embolism blocking a cerebral artery. Haemorrhagic strokes (13%) result from arterial rupture, either intracerebral or subarachnoid. Major modifiable risk factors for ischaemic stroke: hypertension (the single most important), atrial fibrillation (causing cardioembolic stroke; increases risk 4–5 fold), diabetes, smoking, dyslipidaemia, physical inactivity, obesity, and heavy alcohol use. Hypertension control alone reduces stroke risk by 35–45%. Atrial fibrillation should be treated with appropriate anticoagulation (DOACs preferred over warfarin for most patients) to prevent cardioembolic stroke.
Treatment
For ischaemic stroke, intravenous thrombolysis with tPA (tissue plasminogen activator) can dissolve the clot if administered within 4.5 hours of symptom onset. Mechanical thrombectomy — catheter-based mechanical removal of the clot — extends the treatment window to 24 hours for carefully selected patients with large-vessel occlusion and salvageable brain tissue on advanced imaging, producing remarkable neurological recovery rates. Secondary prevention after stroke centres on addressing the underlying cause: antiplatelet therapy for non-cardioembolic ischaemic stroke; anticoagulation for atrial fibrillation; carotid endarterectomy or stenting for significant carotid stenosis; and aggressive risk factor control across all subtypes.
Frequently Asked Questions
What is a TIA and how serious is it?
A TIA (transient ischaemic attack) produces stroke-like symptoms that resolve completely within 24 hours (usually minutes to 1–2 hours) without permanent brain damage. It must be treated as a medical emergency — the ABCD2 score estimates stroke risk at 2 and 7 days, which can be as high as 10–20%. Same-day evaluation including neuroimaging and cardiac monitoring is now standard practice to identify and treat the underlying cause before a completed stroke occurs.
Can young people have strokes?
Yes. Approximately 10–15% of strokes occur in adults under 45. Causes in younger patients differ from the elderly: patent foramen ovale (PFO), arterial dissection, hypercoagulable states, illicit drug use, and oral contraceptive use in women with migraine with aura are more prominent. Cardioembolic sources and atrial fibrillation are also increasingly detected in younger adults.
Sources
- WHO. Stroke factsheet. 2023.
- Powers WJ, et al. 2019 AHA/ASA Acute Ischaemic Stroke Guidelines. Stroke. 2019.
- CDC. Stroke facts. 2023.