The signs of stroke come on suddenly and typically affect one side of the body. The most recognizable are facial drooping, arm weakness, and slurred speech, but strokes can also cause vision changes, loss of balance, and a severe headache with no known cause. Recognizing these signs quickly matters because treatment is most effective within the first few hours.
The BE FAST Warning Signs
Health organizations use the acronym BE FAST to help people spot a stroke. Each letter corresponds to a specific symptom to check for:
- Balance: Sudden loss of balance or coordination, trouble walking, or unexplained dizziness.
- Eyes: Sudden blurred vision, double vision, or loss of sight in one or both eyes.
- Face drooping: One side of the face droops or feels numb. If you ask the person to smile, their smile will look uneven.
- Arm weakness: One arm feels weak or numb. If the person raises both arms, one drifts downward.
- Speech difficulty: Words come out slurred or garbled. The person may struggle to repeat a simple sentence.
- Time: Call 911 immediately if any of these symptoms appear.
These signs can occur alone or in combination. A person having a stroke might show only one or two of them. The key feature is that they appear suddenly, not gradually over days or weeks.
The “Worst Headache of Your Life”
A hemorrhagic stroke, caused by bleeding in or around the brain, often announces itself with a thunderclap headache. This is an extremely severe headache that reaches peak intensity within 60 seconds and lasts at least five minutes. People consistently describe it as the worst headache they’ve ever experienced, completely unlike a migraine or tension headache.
This type of headache can occur with or without the other classic stroke symptoms. Because roughly 15% of strokes involve bleeding rather than a clot, this sudden, explosive headache should always be treated as an emergency.
Symptoms That Are Easy to Miss
Not every stroke looks like the textbook version. Strokes affecting the back of the brain (the posterior circulation) can produce symptoms that mimic inner ear problems or other conditions. Severe vertigo, intense nausea, and loss of coordination sometimes occur without any obvious face drooping or arm weakness. Fewer than 20% of stroke patients presenting with acute vertigo show the classic focal neurological signs that make stroke easy to identify. That means a stroke can score a zero on standard screening scales and still be happening.
These posterior strokes sometimes cause symptoms that look remarkably like an inner ear disorder, including spinning dizziness and even hearing loss on one side. The distinguishing factor is usually the sudden onset and the presence of subtle coordination problems, like difficulty walking a straight line or trouble with fine hand movements.
How Symptoms Differ in Women
Women are more likely than men to experience atypical stroke symptoms. Research from Harvard Health found that women have a higher risk of showing generalized symptoms not obviously linked to one area of the brain. These include sudden confusion, unexplained fatigue, general weakness, headache, altered mental state, or loss of consciousness.
Women still experience the classic signs like face drooping and speech problems, but these less specific symptoms can appear alongside them or, in some cases, dominate the picture. This makes stroke in women easier to dismiss as something less serious, which can delay treatment.
Transient Ischemic Attack: The Warning Stroke
A transient ischemic attack, often called a mini-stroke or TIA, produces the same symptoms as a full stroke but they resolve on their own, usually within minutes. Most TIA symptoms disappear within an hour, and rarely do they last beyond 24 hours.
The danger of a TIA is what it predicts. About 1 in 3 people who have a TIA will eventually have a full stroke, and roughly half of those strokes happen within a year. A TIA is not a minor event. It’s a clear warning that the conditions for a major stroke are already in place, and it calls for the same emergency response as a stroke itself.
Why Every Minute Counts
The reason speed matters comes down to treatment windows. For strokes caused by a blood clot, clot-dissolving medication is most effective when given within 4.5 hours of symptom onset. For certain patients, advanced brain imaging can extend that window to 9 hours. When a large blood vessel in the brain is blocked, a procedure to physically remove the clot can be performed up to 24 hours after symptoms begin, but outcomes are far better with earlier treatment.
Every minute of delayed treatment means more brain tissue is permanently damaged. Calling 911 rather than driving to the hospital is important because paramedics begin assessment in the ambulance and can route the patient to a hospital equipped to handle strokes, rather than a closer facility that may not have the right capabilities.
What Not to Do
If you suspect someone is having a stroke, do not give them aspirin before they reach a hospital. While aspirin can help with clot-based strokes by preventing further clotting, it will worsen a hemorrhagic stroke by increasing bleeding. There’s no way to tell which type is occurring without a brain scan. A hospital will image the brain first, then decide on treatment.
Note the time when symptoms first appeared, or when the person was last seen acting normally. This “last known well” time directly determines which treatments are available. If the person is conscious, have them sit or lie down in a comfortable position. Do not let them eat or drink anything, as stroke can impair swallowing.
Stroke Can Happen at Any Age
Stroke risk increases with age, but it is not limited to older adults. In 2014, 38% of people hospitalized for stroke were younger than 65. Younger adults sometimes delay seeking help because they assume they’re too young for a stroke, which costs them the treatment time that matters most. The symptoms are the same regardless of age: sudden onset of any combination of face drooping, arm weakness, speech difficulty, vision changes, balance problems, or severe headache.