Stroke is known as the illness that "strikes out of nowhere," but in reality the body often signals first. The trouble is that those signals can vanish within minutes, so people shrug them off as tiredness.
With stroke, time is brain tissue. Simply recognizing the signs changes the outcome completely.
Memorize FAST
F (Face): one side of the mouth droops when smiling
A (Arm): hold both arms out — one drifts down
S (Speech): slurred speech, or trouble understanding or forming words
T (Time): any one of these means call emergency services immediately
(In Korea the same check is taught as "이웃손발시선," which adds a fourth sign: the gaze pulling to one side or losing half the visual field.)
The 4.5-hour golden window
For ischemic stroke — the most common type — intravenous clot-dissolving treatment can begin within 4.5 hours of symptom onset. Past that, clot-removal via catheter may still be possible for a limited time, but the later it starts, the weaker the benefit and the greater the disability.
This is why noting the time symptoms began matters so much — it determines which treatment is possible. "Around 3:20 pm" helps far more than "I'm not sure when."
The most dangerous assumption — when symptoms disappear
When symptoms appear and then resolve on their own within minutes to hours, that's a transient ischemic attack (TIA, or "mini-stroke"). It's tempting to feel relieved, but it's actually a warning that a major stroke may be coming. Even if you feel fine, get evaluated at a hospital.
Other symptoms to watch
- Weakness or numbness on one side of the body (one-sided is the hallmark)
- Sudden severe dizziness or loss of balance
- A thunderclap headache unlike anything before (possible hemorrhage)
- Sudden double vision
What to do
- Call emergency services immediately — safer than driving, and paramedics route to a stroke-capable hospital.
- Don't give food or drink — swallowing may be impaired.
- Folk remedies like pricking fingertips only waste time.
- Lay the person flat and comfortable and loosen tight clothing.
Risks you can lower in advance
The single biggest risk factor is high blood pressure, followed by diabetes, dyslipidemia, atrial fibrillation and smoking. Most of these show up in routine health check-ups. Atrial fibrillation especially raises stroke risk without symptoms, so an irregular pulse deserves a visit.
FAQ
Is dizziness alone a stroke?
Dizziness has many causes. But if it comes with slurred speech or one-sided weakness, call emergency services at once.
Can young people have strokes?
It's less common but it happens. With hypertension, smoking or arrhythmia, age doesn't exempt you.
Symptoms started during sleep and I don't know when.
Report the last time you were known to be well. Imaging then helps determine what treatment is possible.
Stroke is a disease of recognition speed. If even one FAST sign appears, don't wait and watch — call for help.
This is general health information and does not replace medical diagnosis or treatment. If emergency symptoms are suspected, contact emergency services without delay.
