A mini stroke, known medically as a transient ischemic attack (TIA), typically lasts only a few minutes. Most symptoms disappear within an hour, though they can persist for up to 24 hours. The brevity is what distinguishes a TIA from a full stroke, but the short duration doesn’t mean it’s harmless. A mini stroke is a warning that a full stroke may follow.
Why Symptoms Are So Brief
A mini stroke happens when blood flow to part of the brain is temporarily blocked, usually by a small clot. Unlike a full stroke, the blockage clears on its own before it kills brain tissue. Blood flow resumes, and symptoms fade. Think of it like a momentary kink in a garden hose that works itself loose.
That said, the line between a TIA and a stroke isn’t always clean. Brain imaging studies show that between 2% and 48% of people who meet the clinical definition of a TIA actually have small areas of permanent brain damage visible on scans. The probability of finding damage on imaging increases when symptoms last longer than one hour. So while the traditional definition of a TIA is “symptoms that resolve within 24 hours,” the reality is more nuanced. Some mini strokes leave a mark even when the person feels completely fine afterward.
What a Mini Stroke Feels Like
The symptoms of a mini stroke are identical to those of a full stroke. The difference is that they go away. Common signs include:
- Sudden weakness or numbness on one side of the face, arm, or leg
- Difficulty speaking or understanding speech
- Vision changes in one or both eyes
- Dizziness or loss of balance
- Sudden severe headache with no obvious cause
These symptoms often appear without warning, peak quickly, and then vanish. Many people dismiss a mini stroke because they feel normal again within minutes. That’s a dangerous instinct. You cannot tell the difference between a mini stroke and a full stroke while it’s happening, and the fact that symptoms resolved doesn’t eliminate the risk of what comes next.
The Real Danger: What Happens After
A mini stroke is less of a diagnosis and more of a countdown. The 90-day stroke risk after a TIA can be as high as 17.8%, and almost half of those strokes happen within just two days. In one large population study, the stroke risk was 2.5% within 48 hours, 5.6% within a week, and 11.2% within 90 days.
Those numbers make a strong case for treating a TIA as a medical emergency, even if your symptoms have completely resolved by the time you reach a hospital. Emergency evaluation isn’t about treating the mini stroke itself. It’s about identifying why it happened and preventing the full stroke that often follows.
How Doctors Assess Your Risk
After a TIA, doctors use a scoring system to estimate your near-term stroke risk. It factors in five things: whether you’re over 60, whether your blood pressure is elevated (above 140/90), what type of symptoms you had (one-sided weakness scores higher than speech problems alone), how long your symptoms lasted, and whether you have diabetes. The longer your symptoms lasted and the more of these factors apply to you, the higher your risk of a full stroke in the days ahead.
Imaging also plays a key role. Brain scans can reveal whether the TIA caused any visible damage and help identify the source of the blockage, whether that’s a narrowed artery, a heart rhythm problem, or a clot that traveled from elsewhere in the body. These findings shape the prevention plan.
Preventing a Full Stroke After a TIA
Treatment after a mini stroke focuses almost entirely on prevention. The specific approach depends on what caused the blockage, but for most people it involves blood-thinning medication started quickly, often within 24 hours. For higher-risk TIAs, doctors may use a combination of two blood thinners for a short window of about 21 days, then switch to a single one for the long term. Using two blood thinners beyond 90 days increases bleeding risk without additional stroke protection.
Beyond medication, the workup after a TIA often uncovers treatable conditions you may not have known about. Uncontrolled high blood pressure, irregular heart rhythms, high cholesterol, and diabetes all raise stroke risk significantly. Managing these conditions is the long game of stroke prevention, and a TIA is often the event that brings them to light.
Why You Shouldn’t Wait It Out
The most common mistake people make with a mini stroke is waiting to see if it happens again. Because the symptoms resolve so quickly, it’s tempting to chalk it up to stress, fatigue, or “just a weird episode.” But the biology is clear: something briefly cut off blood to your brain, and whatever caused it is likely still present. The window after a TIA is when intervention is most effective and most urgent. Getting evaluated within hours, not days, gives you the best chance of avoiding a full stroke.