Stroke
A brain attack — and largely preventable
What it is
A stroke is a sudden interruption of blood supply to part of the brain. About 85% are ischaemic (a clot blocking an artery) and the rest are haemorrhagic (a bleed). Brain tissue dies quickly without blood, which is why stroke is a time-critical emergency — the phrase clinicians use is 'time is brain'.
Why it matters
Stroke is a leading cause of death and the leading cause of acquired adult disability — and it is one of the most preventable serious diseases there is. Large international studies attribute the overwhelming majority of stroke risk to a handful of modifiable factors, with high blood pressure by far the largest. Most people think of stroke as sudden and random. It is sudden. It is rarely random.
What BioSignal knows about treating this
What works for Stroke
BioSignal’s clinical summary, most important first.
- EMERGENCY: thrombolysis and mechanical thrombectomy for ischaemic stroke — both are time-critical
- Blood pressure control — the single highest-value preventive lever
- Anticoagulation for atrial fibrillation (NOT aspirin — see the AF page)
- Statins / ApoB lowering
- Smoking cessation
- Treating obstructive sleep apnoea
- Reducing alcohol
- Physical activity and weight management
- Carotid intervention in selected patients
Signal Records relevant to this condition
Interventions and contributing factors — some of these records describe a cause rather than a cure. The rating shown is BioSignal’s confidence in that Signal Record, not a claim about how well it treats this condition. Open any of them for the full evidence.
- Blood Pressure MedicationHigh confidence
Among the highest-value medicines ever made. The evidence isn't the problem — about half of people stop taking them, and that's where the strokes are.
- StatinsHigh confidence
Proven, proportional reduction in cardiovascular events and mortality by lowering LDL/ApoB; well-characterized, mostly manageable safety profile.
- AlcoholHigh confidence
A Group 1 carcinogen with dose-dependent harms. The heart-protection belief does not survive the methods designed to test it. Cutting back helps, even without quitting.
- Citicoline (CDP-Choline)Limited evidence
The best-evidenced popular nootropic, but mixed — a modest signal in vascular cognitive impairment, weak evidence in healthy adults, no dementia prevention.
- AnticoagulantsHigh confidence
Among the most effective drugs in medicine — roughly a two-thirds reduction in AF stroke. The complexity is not whether they work; it is which one, for whom, and what else you are taking.
New to this? Read these first
How this usually unfolds
- Recognize risk factors
- Get diagnosed
- Track key biomarkers
- Lifestyle first
- Evidence-based treatment
- Long-term monitoring
Who is at risk
- High blood pressure — by a wide margin the single largest contributor
- Atrial fibrillation (raises stroke risk roughly fivefold, and is often silent)
- Smoking
- Diabetes and insulin resistance
- High ApoB / LDL cholesterol
- Obesity and physical inactivity
- Excess alcohol
- Obstructive sleep apnoea
- Prior stroke or transient ischaemic attack (TIA)
How it's diagnosed
Stroke is a clinical emergency recognised by sudden onset of focal neurological deficit — the FAST test (Face drooping, Arm weakness, Speech difficulty, Time to call emergency services). Urgent brain imaging (CT or MRI) distinguishes ischaemic from haemorrhagic stroke, because the treatments are opposite: one is treated by dissolving or removing a clot, the other would be catastrophically worsened by it.
Key biomarkers
Lifestyle
Explore this condition across BioSignal
Related Foundations
Related Signal Records
Related body systems
Frequently asked questions
How much of my stroke risk can I actually change?
Far more than most people assume. Large international case-control research attributes the great majority of stroke risk to a small number of modifiable factors — high blood pressure above all, then smoking, diabetes, lipids, obesity, inactivity, alcohol, and atrial fibrillation. Stroke arrives suddenly, which makes it feel random. It usually isn't. It is the end of a long, silent process you can interrupt.
What is the single most effective thing I can do?
Get your blood pressure down and keep it down. It is the dominant modifiable driver of stroke, and lowering it works — this is one of the most reliably proven things in medicine. If you have been prescribed blood pressure tablets and stopped taking them because you felt fine, that is the highest-value thing you could revisit.
What should I do if I think someone is having a stroke?
Call emergency services immediately — do not wait to see if it passes, and do not drive them yourself. Remember FAST: Face drooping, Arm weakness, Speech difficulty, Time to call. Clot-busting drugs and clot-removal procedures work within a narrow window, and every minute of delay costs brain tissue that does not come back.
I had a TIA — a 'mini-stroke'. Does that matter?
Enormously, and it is frequently underplayed. A TIA is a warning shot: the symptoms resolve, but the risk of a full stroke in the following days is substantially elevated. It warrants urgent assessment, not a wait-and-see. The good news is that the interval is exactly when prevention has the most to offer.
Evidence summary
The causal contribution of hypertension, atrial fibrillation, smoking, diabetes, dyslipidaemia, obesity, inactivity, and alcohol to stroke is well established, with large international studies attributing the majority of population stroke risk to modifiable factors. Blood-pressure lowering has strong randomised evidence for stroke prevention. Anticoagulation in atrial fibrillation dramatically reduces stroke risk. Thrombolysis and mechanical thrombectomy have strong randomised evidence in acute ischaemic stroke and are highly time-dependent.
References & sources
- INTERSTROKE — modifiable risk factors and population attributable risk for stroke
- AHA/ASA Guidelines for the Prevention and Early Management of Stroke
- Thrombectomy trials in acute ischaemic stroke
- Blood-pressure lowering trials and stroke outcomes
Educational information — not medical advice
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