Home / Conditions / Stroke
Blood flow to part of the brain stops — either a vessel is blocked or one has burst. Brain tissue begins dying within minutes, which is why stroke is the one condition on this site where the right response is an ambulance, not an appointment.
If you see any one of these, call an ambulance immediately. Do not wait to see whether it passes, and do not drive to hospital yourself.
Ask them to smile. Does one side droop?
Ask them to raise both arms. Does one drift down?
Ask them to repeat a phrase. Is it slurred or strange?
Any one of these — call 995 now.
Note the time symptoms started. It is the single most useful piece of information you can give the hospital, because the treatments that reverse a stroke only work within a limited window from that moment.
Call 995A stroke — sometimes called a brain attack — happens when blood flow to part of the brain is interrupted. Without blood the affected area loses its oxygen supply and begins to die, which is why the symptoms appear abruptly and why the delay before treatment determines how much recovers.
There are two mechanisms, and they are opposites.
Most ischemic strokes begin years earlier, with atherosclerosis — fatty plaque building up in an artery wall and narrowing it. A narrowed artery alone may cause no symptoms at all.
The stroke happens when that plaque ruptures. The body responds as it would to any injury, by forming a clot — and the clot blocks the already-narrowed vessel. Blood flow stops, and the brain downstream begins to die. A clot can also travel from elsewhere, commonly from the heart in an irregular rhythm.
A haemorrhagic stroke is the opposite failure: the vessel wall gives way and blood escapes into the brain tissue or the space around it. Pressure builds, and the damage comes both from the bleeding and from that pressure.
This is also why blood pressure matters so much on both counts — it accelerates the narrowing and it is the commonest cause of the rupture.
| Ischemic stroke | Haemorrhagic stroke | |
|---|---|---|
| What happens | A vessel is blocked, usually by a clot | A vessel bursts and bleeds |
| How common | The large majority of strokes | Less common, but often more severe |
| Usual causes | Clot from a narrowed artery or from the heart | High blood pressure, a brain aneurysm, or malformed vessels |
| Acute treatment | Aimed at removing or dissolving the clot | Aimed at stopping the bleeding and relieving pressure |
| Neurosurgical role | Occasionally | Frequently |
The two cannot be told apart by symptoms alone — which is why the first thing done at hospital is a scan. Treating one as the other would be dangerous, so nothing can be given until the type is known. It is another reason the ambulance matters more than any decision made at home.
The defining feature is that everything comes on suddenly.
Less commonly, sudden nausea and vomiting, or a brief loss or clouding of consciousness.
A TIA, or mini-stroke, produces the same symptoms but they resolve — often within minutes, sometimes within an hour. Because everything returns to normal, people commonly decide it was nothing and carry on.
A TIA is a warning, and the risk of a full stroke is highest in the days immediately afterwards. Symptoms that came on suddenly and then resolved still need urgent assessment — that is the window in which a stroke can be prevented rather than treated.
In the acute setting this happens at hospital, quickly, and the priority is establishing which type of stroke it is.
A stroke happening now is managed by the hospital's emergency and stroke team, and nothing on this page should delay a call to 995. Seeing a stroke specialist is what comes either side of that. Dr Tung is a neurosurgeon, and his involvement sits at four specific points — three of them after the acute event, one of them before it ever happens.
Where a scan has shown a brain aneurysm, an arteriovenous malformation, or narrowing that raises concern, the question is whether to treat it or monitor it. Treating an aneurysm before it ruptures is the clearest example of preventing a haemorrhagic stroke rather than responding to one, and it is core neurosurgical work.
When a stroke is caused by bleeding rather than a blockage, the treatment is frequently surgical — securing a ruptured aneurysm, dealing with a malformation, or relieving the pressure that bleeding creates inside the skull. Dr Tung treats aneurysms both before and after rupture, including with flow-diverting stents and flow disruptors.
Discharge from hospital often comes with a diagnosis but not always a complete answer as to cause — particularly in younger patients, where a vessel tear, a malformation or a structural abnormality may be behind it. Identifying that is what determines whether the next one can be prevented, and it needs imaging read by someone who treats these things surgically.
Persistent headache, dizziness, balance problems and nerve pain are common after a stroke and are frequently accepted as permanent because the acute phase is over and nobody revisited them. They are treatable in their own right, and Dr Tung's practice includes the interventional options — nerve blocks, pulsed radiofrequency and neuromodulation — used when medication has not worked.
What a consultation produces. An explanation of what caused your stroke as far as the imaging allows; whether anything structural remains that needs treating; a plan for the risk factors that are within your control; and treatment for whatever symptoms are still there. Bring the discharge summary and the scan images — the images themselves, not only the report.
Stroke is substantially preventable, and the same factors matter whether or not you have had one:
| Commonly believed | Actually |
|---|---|
| Stroke cannot be prevented | It is largely preventable |
| Stroke cannot be treated | It is treatable, and urgently so |
| Stroke only affects the elderly | It can happen at any age |
| Stroke happens in the heart | It happens in the brain |
| Recovery stops after a few months | Recovery can continue for years |
| If symptoms pass, it was nothing | That is a TIA, and it needs urgent assessment |
Ischemic stroke is caused by a blockage cutting off blood supply, and accounts for the large majority. Haemorrhagic stroke is caused by a vessel bursting and bleeding. They cannot be distinguished by symptoms, only by a scan — and their treatments are opposite, which is why that scan comes first.
Yes, urgently. Symptoms that resolve are a transient ischemic attack, and the risk of a full stroke is highest in the days that follow. It is the best opportunity there is to prevent one.
The treatments that can reverse an ischemic stroke only work within a limited window measured from when symptoms began. If nobody knows when that was, those options may not be available.
Yes. It is less common but it happens, and in younger people the causes are more often things like a vessel tear, a clotting disorder or a structural abnormality — which is a reason to investigate the cause thoroughly rather than assume.
The risk of a second stroke is higher than the risk of the first, and much of it is modifiable — blood pressure, smoking, heart rhythm, diabetes and cholesterol. That is what post-stroke assessment is for.
Not to see a stroke specialist here. Bring any hospital records, discharge summaries and scans. In an emergency, call 995 rather than the clinic.
Brain aneurysm · Headaches (all types) · Dizziness and vertigo · Concussion · Neuropathic pain · Neurosurgery
See a stroke specialist to establish why it happened, whether anything structural still needs treating, and what can be done about the symptoms that are still there. Bring your discharge summary and the scan images.
