Understanding stroke: Warning signs and how to prevent one

A face suddenly looks uneven. Someone struggles to finish a sentence. An arm feels weak for no obvious reason. These changes can be easy to explain away, especially when the person seems otherwise well.

With stroke, waiting can cost precious time.

If you suspect a stroke, call 112 from a cellphone or 10177 for an ambulance in South Africa immediately. Do this even if the symptoms disappear.

Stroke is a medical emergency, but there is also much you can do before one happens. Understanding both the warning signs and the everyday risks gives you a practical starting point.

What Happens During a Stroke?

A stroke occurs when blood flow to part of the brain is interrupted or a blood vessel bleeds in or around it. Brain tissue can become damaged, affecting movement, speech, vision, memory and other functions.

There are two main types. An ischaemic stroke happens when a vessel supplying the brain becomes blocked, usually by a clot. This is the more common type.

A haemorrhagic stroke happens when a blood vessel ruptures and causes bleeding.

The symptoms can overlap, so you cannot reliably identify the type at home. Hospital assessment and brain imaging are essential because treatments differ.

Recognise the Signs: Think BE FAST

Stroke symptoms usually begin suddenly. The BE FAST reminder includes problems with balance and vision, alongside the familiar face, arm and speech changes.

Other signs include sudden weakness or numbness in a leg, particularly on one side, and a sudden severe headache without an obvious cause.

You do not need every symptom to suspect a stroke. Some strokes cause prominent vision or balance problems without obvious facial drooping. Stroke can also happen in younger adults.

What Should You Do Immediately?

Call for an ambulance and say you suspect a stroke. Give your location clearly, including landmarks where needed.

Note when symptoms started. If this is uncertain, record when the person was last known to be well. For someone who wakes with symptoms, that may be before they went to sleep.

Do not wait for a routine appointment, let the person drive or encourage them to sleep it off.

While waiting, keep them safe and follow the emergency dispatcher’s instructions. Avoid giving food or drink because swallowing may be impaired. Do not give aspirin or other medication unless instructed by a healthcare professional: aspirin can worsen a bleeding stroke.

If the person becomes unresponsive, tell the dispatcher immediately. They can guide you through positioning or CPR, depending on whether the person is breathing normally.

What If the Symptoms Go Away?

A transient ischaemic attack, or TIA, causes temporary stroke-like symptoms when blood flow to part of the brain is briefly interrupted.

It is sometimes called a “mini-stroke”, but that term can make it sound harmless. A TIA can warn of a subsequent stroke, with risk particularly high soon afterwards.

At home, you cannot establish whether disappearing symptoms represent a TIA, a stroke or another condition. Improvement does not make it safe to delay care.

Urgent assessment can identify causes such as narrowed arteries or an abnormal heart rhythm and allow preventive treatment to begin.

Why Does Fast Treatment Matter?

For an ischaemic stroke, eligible patients may receive medicine that dissolves the clot. This is commonly given within 4.5 hours of symptom onset, although selected patients may qualify later following specialised imaging.

Some people with a blocked major brain artery can undergo mechanical thrombectomy, a procedure that removes the clot. Selected patients may benefit up to 24 hours after onset.

These windows are not reasons to wait. Earlier treatment generally offers better opportunities to preserve brain function.

Bleeding strokes require different management, which may include blood-pressure control, reversal of anticoagulant effects or surgery. Seek emergency care regardless of how much time has passed.

Start Prevention With Your Blood Pressure

High blood pressure is a leading modifiable stroke risk factor. It damages blood vessels and increases the likelihood of both blockage and bleeding.

It often causes no noticeable symptoms, so feeling healthy does not tell you whether yours is controlled.

Have your blood pressure checked at a clinic, pharmacy or GP practice. If it is elevated, arrange follow-up rather than relying on one reading. Your clinician can advise on repeat measurements, home monitoring and an appropriate target.

Take prescribed treatment consistently. If side effects, costs or collecting refills become difficult, discuss those barriers with your healthcare team. Stopping medication can undermine protection even when you feel well.

Check the Risks You Cannot See

Diabetes and high cholesterol can increase stroke risk. Testing should reflect your age, medical history and overall cardiovascular risk.

Managing diabetes involves more than blood sugar alone: blood pressure, cholesterol and smoking also matter. Cholesterol-lowering medication may be recommended according to your risk.

Atrial fibrillation, an irregular heart rhythm, can allow clots to form in the heart and travel to the brain. Some people notice palpitations; others have no symptoms. When appropriate, anticoagulant medication substantially reduces stroke risk.

Tell your clinician about a previous TIA or stroke, family history and pregnancy-related high blood pressure. These details can influence your prevention plan.

Build Habits That Protect Your Blood Vessels

Aim for at least 150 minutes of moderate activity each week, such as brisk walking, and include strength training on two days. Start gradually and break up long periods of sitting.

Choose an eating pattern rich in vegetables, fruit, beans, whole grains, nuts and fish. Mediterranean-style eating has evidence for stroke prevention, but it can use familiar, affordable foods: lentils, oats, seasonal vegetables and pilchards.

Reduce salt, including that in stock powders, processed meats, packet soups and salty snacks.

If you smoke, seek support to quit. Avoid heavy drinking and binge drinking; alcohol can increase blood pressure and contribute to abnormal heart rhythms.

Regular sleep matters too. Loud snoring, breathing pauses and daytime sleepiness warrant assessment for sleep apnoea.

Prevention Is Personal

Do not start daily aspirin yourself to prevent a first stroke. Its bleeding risks can outweigh its benefits.

After a stroke or TIA, prevention depends on the cause. Treatment may include antiplatelet medication, anticoagulants, cholesterol treatment or a procedure for selected patients.

Healthy habits support this care, but do not replace prescribed treatment. Arrange a risk assessment, keep up with follow-up appointments and make sure your household knows the warning signs and emergency numbers.