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STROKE SERIES · ARTICLE 3 OF 12
The three kinds of stroke
Ischaemic, haemorrhagic and TIA.
When we say “stroke”, we are actually talking about three different conditions that produce similar symptoms but happen for opposite reasons. Two of them are caused by blood not getting to part of the brain — one because something has blocked the artery, one because the artery itself has burst. The third is a stroke that resolves on its own, but is the most important warning sign in medicine.
Knowing which kind a person has had makes a big difference to treatment, recovery, and prevention of the next one. That’s why the first thing that happens at hospital after a suspected stroke is a CT scan of the brain — to tell the three apart and decide what to do.
The three at a glance
Ischaemic stroke — a clot blocks an artery. The brain tissue downstream of the blockage starts dying. About 80% of strokes.
Haemorrhagic stroke — an artery in the brain bursts. Blood floods the brain tissue. About 20% of strokes.
TIA (mini-stroke) — the same as an ischaemic stroke, but the blockage clears on its own within minutes to hours. Symptoms come and go. A warning sign — not a stroke that didn’t matter.
1. Ischaemic stroke — the blockage kind
Ischaemic stroke
80% OF STROKES
An artery somewhere in the brain — or in the neck arteries that supply the brain — gets blocked. The brain tissue downstream of the blockage is starved of oxygen, and the cells begin to die within minutes.
Ischaemic strokes are the kind we can treat with clot-busting drugs (thrombolysis) and mechanical clot retrieval (thrombectomy) — but only inside specific time windows. They are also the kind that aspirin and statins prevent.
How the blockage forms — three main ways
Ischaemic strokes happen in three main mechanisms, all of which look the same from outside but need slightly different prevention strategies.
Thrombotic — the clot forms in the brain artery itself
Years of high cholesterol, high BP and smoking damage the artery walls in and around the brain. Plaque builds up. Eventually a plaque cracks open, the body forms a clot on top of it, and the artery blocks. This is similar to how a heart attack happens, just in a brain artery instead of a coronary artery.
People at highest risk: long-standing high BP, high cholesterol, diabetes, smokers.
Prevention: BP, cholesterol and blood sugar control; quitting smoking; the food and walking work in articles 8 and 9 of this series.
Embolic — the clot travels from somewhere else
A clot forms in the heart or in one of the big neck arteries (carotids) and travels up to the brain, where it lodges in a smaller artery and blocks it. The brain artery itself may have been perfectly healthy.
The two most common sources are:
• Atrial fibrillation (AFib). An irregular heartbeat causes blood to pool in one of the heart chambers, where a clot can form. About 1 in 5 South African strokes come from AFib. Often undiagnosed — and easily treated with anticoagulant tablets once it’s known.
• Carotid artery disease. Plaque in the carotid arteries (the big arteries in the neck) cracks, a small clot forms, and it flicks up into the brain. Often preceded by a TIA.
Prevention: treating AFib with anticoagulants (warfarin or one of the newer DOACs — apixaban, rivaroxaban, dabigatran); carotid surgery in selected cases; the usual food, walking and statin work.
Small vessel (lacunar) stroke
One of the tiny blood vessels deep inside the brain gets blocked. The stroke is small but in an important place. Often these strokes cause specific symptoms — a weak hand without speech problems, or a numb leg without face droop. Driven primarily by long-standing high BP and diabetes.
Prevention: tight BP control, blood sugar control, statin therapy.
Cryptogenic — when we don’t know
In about 1 in 4 ischaemic strokes, no clear cause is found after investigation. These are called “cryptogenic”. Sometimes a hidden AFib emerges on longer heart monitoring; sometimes a hole between the heart chambers (patent foramen ovale) is found; sometimes the cause is never identified. Prevention still focuses on the usual levers, plus a closer look for AFib.
2. Haemorrhagic stroke — the bleeding kind
Haemorrhagic stroke
20% OF STROKES
An artery in or around the brain bursts. Blood floods into the brain tissue instead of flowing through it. The bleeding compresses surrounding brain tissue, raises the pressure inside the skull, and damages the brain.
Haemorrhagic strokes are less common than ischaemic but more often fatal — about 30 – 50% in the first month. They are not treated with thrombolysis (which would make the bleeding worse) and require different care: BP control, sometimes surgery, often a longer hospital stay.
Two kinds of haemorrhagic stroke
Intracerebral haemorrhage (ICH) — bleeding within the brain
A small artery deep in the brain bursts. This is almost always driven by long-standing, poorly controlled high blood pressure. The artery walls become fragile after years of high pressure and eventually one tears.
Symptoms come on suddenly — usually a severe headache combined with the F.A.S.T. signs from article 2, often with vomiting and loss of consciousness if the bleed is large.
ICH is by far the most preventable kind of stroke. Good BP control prevents the vast majority. This is one of the reasons the BP series matters so much.
Subarachnoid haemorrhage (SAH) — bleeding around the brain
An artery on the surface of the brain ruptures — usually a weak point in the artery wall called an aneurysm. Blood floods into the space between the brain and the skull.
The classic presenting symptom is a sudden, severe headache — often described as “the worst headache of my life” or “like being hit on the back of the head”. The medical term is “thunderclap headache”. It comes on in seconds, peaks within a minute, and is unmistakable for most patients.
SAH affects younger people more often than other strokes (peak age 40 – 60), is more common in smokers, women, and people with a family history. It is a true emergency — even patients who initially look stable can deteriorate quickly. About 30% of SAH patients die before reaching hospital; another 30% die in hospital. Of those who survive, recovery is often slow.
The thunderclap headache
A headache that comes on in seconds, reaches its worst within a minute, and is by far the worst headache you have ever experienced — call 10177 immediately. This could be a burst aneurysm. The time window for treatment is short.
Migraines, tension headaches and cluster headaches build up over minutes to hours. A thunderclap headache feels like being hit on the back of the head with a hammer. Most people instinctively know it is different.
3. TIA — the warning kind
Transient ischaemic attack (TIA)
A WARNING, NOT NOTHING
A TIA is an ischaemic stroke that resolves on its own. An artery temporarily blocks (or partially blocks), causes stroke symptoms, and then the blockage clears — usually within minutes, occasionally up to 24 hours. By the time the patient is checked, everything looks normal.
The danger of a TIA is not the TIA itself. The danger is what it predicts. About 1 in 5 people who have a TIA will have a full stroke within 3 months — and roughly half of those second strokes happen within 48 hours. With urgent investigation and treatment, most of those second strokes can be prevented.
What a TIA feels like
Exactly like a stroke — face droop, arm weakness, speech problems, vision changes — but the symptoms clear up. Common patterns:
• A sudden weakness on one side of the body that lasts 5 to 30 minutes, then goes away.
• Brief slurred speech that resolves within an hour.
• Sudden loss of vision in one eye (described as “a curtain coming down”) lasting a few minutes — called amaurosis fugax. Often a sign of carotid artery disease.
• A few minutes of confusion or difficulty understanding speech.
• A patch of sudden numbness on one side of the body.
People often dismiss these episodes — “I was just tired”, “it was probably a migraine”, “it went away so it must have been nothing”. These episodes are not nothing. They are the brain telling you it is in trouble.
The ABCD² score
Hospitals use a score called ABCD² to estimate how likely a TIA is to be followed by a full stroke in the next 48 hours. Higher scores mean more urgent investigation and treatment. The score uses Age, Blood pressure, Clinical features (weakness vs speech only), Duration, and Diabetes. You don’t need to know the score yourself — but you should know that the higher-risk TIAs need same-day or next-day investigation, usually in a hospital stroke unit.
If you suspect a TIA
Go to a hospital emergency department or stroke clinic the same day. Don’t wait for the next morning. Don’t wait to see if it happens again. The 48 hours after a TIA is the highest-risk period.
If symptoms are still present when you call — treat it as a full stroke. Call 10177.
The three at a glance — a summary table
Feature Ischaemic Haemorrhagic TIA % of strokes \~80% \~20% Warning sign What happens Artery blocked Artery bursts Brief block, clears Typical symptoms F.A.S.T. signs F.A.S.T. + severe headache, vomiting F.A.S.T. signs, resolve \< 24 h Main risks BP, cholesterol, smoking, AFib Esp. high BP; aneurysms (SAH) Same as ischaemic Golden-hour treatment Thrombolysis ± thrombectomy BP control, sometimes surgery Urgent workup 1-month mortality \~10 – 20% \~30 – 50% \~0% if treated
Why distinguishing matters — the CT scan
The treatments for ischaemic and haemorrhagic stroke are completely different. Thrombolysis dissolves clots — exactly what you want for an ischaemic stroke, exactly what you don’t want for a haemorrhagic one. Lowering BP urgently helps stop bleeding in a haemorrhagic stroke, but can make an ischaemic stroke worse by reducing flow to the at-risk brain tissue.
The CT scan tells the two apart. It is almost always the first investigation done at hospital after a suspected stroke. A fresh bleed shows up as a bright white area on a CT scan within minutes. A fresh ischaemic stroke usually shows nothing in the first hour — the CT looks normal — but that absence of bleeding is itself useful information.
Some hospitals also do CT angiography (CTA) — an enhanced scan that shows the arteries themselves — to find where exactly the blockage is and whether the patient is a candidate for thrombectomy. In selected centres, an MRI may also be used.
The South African CT scan landscape
Most district and regional public hospitals have CT scanners. Many tertiary hospitals can do CT angiography. Thrombectomy — the more advanced clot-removal procedure — is available in larger centres including Groote Schuur, Tygerberg, Charlotte Maxeke and several private hospital groups. Article 5 covers the hospital journey in more detail.
What each type means for recovery
Recovery varies enormously between people, but the type of stroke is one of the biggest predictors of how the early recovery will look.
Ischaemic strokes
If treated quickly with thrombolysis or thrombectomy, recovery can be remarkable — some patients walk out of hospital within days with minimal residual disability. Untreated, recovery is slower and less complete, but most patients still regain meaningful function over weeks to months. Small lacunar strokes often recover very well.
Haemorrhagic strokes
The early phase is more dangerous — risk of further bleeding, brain swelling, raised pressure. Patients usually spend longer in hospital and need more intensive monitoring. Recovery, once the patient is stable, can be slower than for ischaemic stroke, but is real. Some haemorrhagic stroke survivors do better than expected, particularly younger patients with smaller bleeds.
TIA
By definition, full recovery — that’s what makes it a TIA rather than a stroke. The recovery work is in preventing the full stroke that may otherwise follow.
The bigger picture
The three kinds of stroke share more than they differ. All three are caused mostly by the same underlying conditions — high BP at the top of the list, then cholesterol, then diabetes, then smoking, then AFib. All three can be largely prevented by managing those conditions well. All three need urgent recognition and rapid hospital care.
The big difference is the immediate treatment. The CT scan in the first hour is what decides. After that, the long-term prevention plan looks very similar regardless of which kind a person had.
The next article in the series takes a closer look at who tends to have strokes and why — the South African risk factor picture, including the conditions you may not have thought of (sickle cell, HIV, AFib, pregnancy) alongside the big three (BP, cholesterol, diabetes).
Where to get more help
In an emergency — 10177 for an ambulance.
Heart and Stroke Foundation South Africa — heartfoundation.co.za · 021 422 1586.
The Stroke Survivors South Africa community — patient and caregiver support.
Phila Today High Blood Pressure Series and Cholesterol Series — recommended companion reading for stroke prevention.
Phila Today Stroke Series — next: the risk factors — who gets a stroke and why.
Phila Today · Article 3 of 12 in the Stroke Series