What Are the Signs of a Stroke? The Four Letters That Save Lives
Short answer: The signs of a stroke are sudden face drooping on one side, weakness or numbness in one arm, and slurred or garbled speech. If you notice any one of these signs, it is time to call 999 immediately. Do not wait for all three signs to appear, and do not wait to see whether the symptoms pass. With a stroke, time lost is brain lost, and acting fast gives the person the best chance of survival and recovery.
Today, Thursday 29 October 2026, is World Stroke Day. It is observed every year on 29 October, and it was established by the World Stroke Organization in 2006 to drive public awareness and action on stroke. The campaign for 2025 to 2026 is called Every Minute Counts, written as Every M1nute Counts, with the hashtags #actFAST and #worldstrokeday. Its message is simple: learn the signs, act fast, and do not delay emergency care.
That message matters because a stroke is a medical emergency, not a condition to watch at home. A stroke happens when the blood supply to part of the brain is cut off, either because a blood vessel is blocked or because a blood vessel in or around the brain ruptures and bleeds. Brain cells depend on a continuous supply of oxygen and nutrients, so when that supply is interrupted, damage begins quickly. The sooner a person reaches hospital care, the greater the opportunity to limit that damage.
What are the signs of a stroke? Learn FAST
The main stroke symptoms can be remembered with the word FAST: Face, Arms, Speech, Time. The NHS describes the test in these terms, and it is the test the World Stroke Day campaign asks everyone to learn.
F is for Face. Has the face dropped on one side? Ask the person to smile. Is the smile uneven, or has the mouth or eye drooped on one side? Facial weakness, including drooping of one side of the face, is one of the most common signs.
A is for Arms. Can the person raise both arms and keep them raised? Arm weakness or numbness in one arm may mean they cannot lift both arms, or one arm drifts downward. Ask them to raise both arms and watch whether one arm stays lower than the other.
S is for Speech. Is speech slurred or garbled, or can the person not talk at all despite appearing to be awake? They may also have problems understanding what is said to them, or difficulty finding words and speaking in clear sentences. Any sudden change in speech counts.
T is for Time. It is time to dial 999 immediately if you notice any of these signs. The NHS advice is explicit: if you see any one of these signs, call 999 straight away. You do not need all three. One sudden FAST symptom is enough to treat the situation as a possible stroke.
That last point is the one most people get wrong. Many people wait, hoping the symptom will pass, or they wait for a second or third sign to confirm what they fear. The campaign exists precisely because that wait costs brain function. If you suspect a stroke, phone 999 immediately and ask for an ambulance, even if you are not sure. Paramedics are trained in stroke care and will make sure the person receives emergency medical care and specialist treatment.
What are the other warning signs of a stroke?
The FAST test helps spot the three most common signs of stroke, but it does not cover every symptom. Stroke symptoms vary from person to person because different parts of the brain control different parts of the body, and symptoms usually begin suddenly, over seconds to a minute or two. Other signs that should always be taken seriously include:
- Sudden weakness or numbness on one side of the body, including the legs, hands or feet.
- Sudden blurred vision or loss of sight in one or both eyes.
- Sudden memory loss or confusion.
- Sudden dizziness, unsteadiness or a sudden fall.
- A sudden, severe headache.
- Sudden difficulty finding words, or a change in sensation in an arm or leg.
If you spot any one of these signs, do not wait. Call 999 straight away. The same rule applies as with FAST: a single sudden symptom is an emergency, not a reason to monitor the person for an hour and see what happens.
What if the symptoms disappear?
Sometimes stroke symptoms disappear quickly, within minutes, or in less than 24 hours. That may mean the person has had a transient ischaemic attack, often called a mini stroke or TIA. A TIA happens when the blood supply to the brain is briefly interrupted and then restored, and it can be a warning sign of a potentially more serious stroke.
The NHS advice here is just as clear as it is for a full stroke. Even if the symptoms disappear while you are waiting for the ambulance, it is still important to go to hospital for an assessment. Do not treat a disappearing symptom as a false alarm. A TIA should be treated as a medical emergency, because it shows there is a problem with the blood supply to the brain and an increased risk of a stroke in the near future. After an initial assessment, the person should be referred to a specialist, and the NHS says that referral should happen within 24 hours of the start of symptoms.
This is a point worth sharing with family members and carers, because they are often the first to notice a change. A small but sudden difference during an ordinary moment, a mug slipping repeatedly from one hand, one sleeve suddenly becoming difficult to manage, or a sentence that comes out garbled, can be the first sign. People who know how someone usually smiles, speaks, moves and manages familiar activities are best placed to spot that change.
What are the two main types of stroke?
There are two main types of stroke, and the distinction matters for treatment, even though the emergency response is the same for both: call 999 at once.
An ischaemic stroke is caused when a blood clot blocks or narrows an artery supplying blood to the brain. It is the most common type of stroke. Conditions such as high blood pressure, high cholesterol and atrial fibrillation, an irregular heart rhythm, increase the risk of an ischaemic stroke.
A haemorrhagic stroke is caused when a blood vessel in or around the brain ruptures, causing bleeding into the brain. Uncontrolled high blood pressure and ruptured aneurysms are important causes.
You do not need to decide which type of stroke is occurring, and you should not try. That is a job for hospital scans and specialists. Your job is recognition and speed: spot a FAST sign, call 999, and note the time the symptoms started if you can, because clinicians will ask when they began.
Why does every minute count?
The World Stroke Day slogan is not a metaphor. Earlier treatment generally offers the best opportunity to limit brain injury, although eligibility for specific treatments depends on the type of stroke, the time course, imaging findings and other clinical factors. Nobody should assume that treatment is no longer possible because several hours have passed, and nobody should delay calling because they think it is already too late. The right response is always the same: seek emergency care immediately.
The scale of the problem in the UK underlines why recognition matters so much. In England, Scotland and Wales, around 100,000 strokes happen every year, according to NHS Wales. Stroke is the fourth single leading cause of death in the UK and the single largest cause of complex disability. Most people who have a stroke are aged 70 and over, but stroke can happen to anyone, of any age, at any time. That is why the campaign asks everyone, not only people at high risk, to learn FAST.
What causes most strokes, and what can be changed?
World Stroke Day is also about prevention, and here the evidence is unusually encouraging. The World Stroke Organization says stroke is highly preventable, and that manageable risk factors account for around 90 percent of all strokes. The large international INTERSTROKE study, which covered tens of thousands of people across 32 countries, reached a similar figure: ten modifiable risk factors together accounted for 90.7 percent of stroke cases, in all regions, in younger and older people, and in men and women.
The ten factors were hypertension (high blood pressure), physical inactivity, poor diet, obesity, smoking, cardiac causes such as atrial fibrillation, diabetes, alcohol intake, stress, and lipids (blood fats). Hypertension was the most important single factor in all regions, with a population attributable risk of 47.9 percent, meaning that a large share of the stroke burden could in principle be reduced if high blood pressure were corrected. Physical inactivity accounted for 35.8 percent, lipids for 26.8 percent, poor diet for 23.2 percent, obesity for 18.6 percent, smoking for 12.4 percent, cardiac causes for 9.1 percent, alcohol intake for 5.8 percent, stress for 5.8 percent, and diabetes for 3.9 percent. These figures overlap, because many risk factors occur together, for example obesity and diabetes, so they do not add up to a simple total.
In practical terms, that means the most useful prevention steps are the unglamorous ones: getting blood pressure checked and treated, staying physically active, eating well, not smoking, limiting alcohol, and managing diabetes and cholesterol. High blood pressure is the priority because it is both the largest factor and often silent: it rises without symptoms, which is why a routine check matters even when you feel well. If you have already had a stroke or a TIA, prevention becomes even more important, and it should be discussed with your GP or stroke team rather than managed alone.
That prevention message links back to our earlier coverage on this site. We have written before about how persistent sleeplessness is linked to higher stroke risk in research, and about hidden heart disease risk in people who are only just above a healthy weight. Those pieces look at risk from the research side. Today is different: it is about the emergency itself, and about what to do in the minutes when recognition is all that matters.
What should you do while waiting for the ambulance?
Once you have called 999, stay with the person and keep them as comfortable as possible. Tell the call handler what you have noticed and when the symptoms started. Do not drive the person to hospital yourself if an ambulance is on its way, and do not leave them alone to fetch help if you can avoid it. If the symptoms disappear, say so, but still go to hospital for assessment, as explained above. Do not wait for a GP appointment the next day when FAST signs are present now: this is a 999 emergency.
It also helps to tell family, friends and colleagues about FAST before an emergency ever happens. The campaign works only if the person standing next to someone having a stroke knows what to look for. Teaching one other person the four letters today, on World Stroke Day itself, is a concrete way to mark the day. Ask them to smile, raise both arms, and repeat a simple sentence, and ask what they would do if any part of that test failed. The correct answer is always the same: time to call 999.
Frequently asked questions
What are the signs of a stroke?
The main signs are sudden face drooping on one side, weakness or numbness in one arm, and slurred or garbled speech. Other signs include sudden weakness or numbness on one side of the body, sudden vision loss, sudden confusion, sudden dizziness or a fall, and a sudden severe headache. If you notice any one of these signs, call 999 immediately.
What does FAST stand for in stroke?
FAST stands for Face, Arms, Speech, Time. Face: has the face dropped on one side, or can the person not smile evenly? Arms: can the person raise both arms and keep them there? Speech: is speech slurred or garbled, or can the person not talk at all? Time: it is time to call 999 immediately if you notice any of these signs.
Should I call 999 if only one FAST sign is present?
Yes. The NHS says to dial 999 immediately if you notice any one of the FAST signs. Do not wait for all three signs to appear, and do not wait to see whether the symptom passes.
What is a mini stroke or TIA?
A transient ischaemic attack, or TIA, is a brief interruption to the blood supply to the brain whose symptoms disappear quickly, within minutes or in less than 24 hours. It should still be treated as a medical emergency and assessed in hospital, because it can warn of a more serious stroke.
Can a stroke happen to a young person?
Yes. Stroke can happen to anyone, of any age, at any time, although most people who have a stroke are aged 70 and over. Sudden FAST signs in a younger person are just as much a 999 emergency.
What causes most strokes?
Ten modifiable risk factors together account for around 90 percent of strokes, according to the World Stroke Organization and the INTERSTROKE study. High blood pressure is the most important single factor, followed by physical inactivity, blood fats, poor diet, obesity, smoking, cardiac causes, diabetes, alcohol and stress.
Related reading: Our earlier piece on the sleep problem linked to a higher stroke risk looks at the research side of stroke risk; our guide to hidden heart disease risk in people just above a healthy weight covers two blood markers worth knowing about; and our Stoptober guide to 28 days smoke-free explains what happens to your body after your last cigarette, since smoking is one of the ten modifiable stroke risk factors.
Sources: World Stroke Organization, World Stroke Day press release on prevention and the 2025-26 Every Minute Counts campaign, https://www.world-stroke.org/news-and-blog/news/world-stroke-day-pr-global-call-for-urgent-action-to-tackle-the-growing-burden-of-stroke ; NHS 111 Wales, stroke symptoms and the FAST test, https://111.wales.nhs.uk/actfast?locale=en&term=a ; NHS South Yorkshire, stroke signs and symptoms including other warning signs, https://southyorkshire.icb.nhs.uk/your-health/stroke-signs-and-symptoms ; NHS Wales (Cwm Taf Morgannwg), Act FAST and annual stroke figures for England, Scotland and Wales, https://ctmuhb.nhs.wales/news/latest-news/act-fast-call-999-if-you-see-any-single-one-of-the-signs-of-a-stroke/ ; INTERSTROKE study summary, ten modifiable risk factors and population attributable risks, https://www.eurekalert.org/news-releases/746329
Medical disclaimer: This article is general information only and is not medical advice. If you suspect a stroke, call 999 immediately. If you are worried about your stroke risk, speak to your GP.
