What Causes a Stroke?

A stroke is often a terrifying and sudden medical emergency, but the risks leading up to it typically build over years. From lifestyle choices to underlying medical conditions and even genetic predisposition, a complex web of factors contributes to its occurrence. Understanding these risks—and, more importantly, addressing them—can make all the difference in protecting yourself or your loved ones.

Let’s break down what causes strokes, explore the types, and dive into practical ways to mitigate your risk.

The Types of Stroke and What Triggers Them

1. Ischemic Stroke: Blocked Blood Flow
Accounting for nearly 87% of all strokes, ischemic strokes occur when a blockage halts blood flow to the brain. These blockages are often caused by:

Atherosclerosis: A build-up of fatty deposits along artery walls, narrowing them and increasing the risk of clots.

Embolisms: Blood clots or debris from other parts of the body (like the heart) that travel to the brain, common in conditions like atrial fibrillation.

2. Hemorrhagic Stroke: Bleeding in the Brain
Though less common, this type of stroke is more severe and often fatal. It happens when a blood vessel in the brain ruptures, leading to dangerous pressure and tissue damage.

High Blood Pressure: Chronic hypertension weakens blood vessel walls, making them prone to rupture.
Aneurysms and AVMs: Abnormal blood vessel formations can burst unexpectedly.

3. Transient Ischemic Attack (TIA): A Warning Sign
Often called a “mini-stroke,” TIAs are temporary blockages causing stroke-like symptoms that resolve within hours. However, they’re a warning of future risks—10% of those who experience a TIA will suffer a stroke within three months.

Health Conditions That Increase Stroke Risk
Several underlying health conditions heighten the likelihood of a stroke. By addressing these, you can significantly reduce your risk:

Hypertension: The leading risk factor, is high blood pressure stresses blood vessels, accelerating conditions like atherosclerosis.

Diabetes: Elevated blood sugar damages vessels, doubling the risk of ischemic stroke.
Atrial Fibrillation (AFib): This irregular heartbeat promotes clot formation, responsible for up to 20% of strokes.

Sleep Apnoea: Disrupted breathing during sleep increases inflammation and blood pressure, contributing to stroke risk.

While medical conditions play a significant role, lifestyle choices can tip the scales:

Diet: Foods high in salt, trans fats, and sugar fuel high blood pressure, obesity, and unhealthy cholesterol levels. Adopting a Mediterranean-style diet, rich in fruits, vegetables, and healthy fats, offers protective benefits.

Physical Inactivity: Regular exercise lowers blood pressure, improves cardiovascular health, and helps regulate weight.

Smoking: Smoking damages blood vessel linings and increases clotting tendencies. Quitting is one of the most powerful changes you can make.

Alcohol and Drugs: Excessive drinking raises blood pressure and weakens vessels, while drugs like cocaine can trigger sudden haemorrhagic strokes.

While some risks are beyond your control, recognising them allows for early intervention:

Age: After 55, stroke risk doubles every decade.

Ethnicity: African Americans and Hispanics face higher risks due to prevalent hypertension and diabetes.

Family History: Genetics influence blood pressure and cholesterol regulation.

New research highlights the role of chronic inflammation and abnormal clotting in stroke development:

Inflammation: Conditions like obesity and autoimmune diseases accelerate atherosclerosis and destabilize plaques, increasing rupture risks.

Clotting Disorders: Genetic mutations, such as Factor V Leiden, make blood prone to clotting, heightening ischemic stroke risks.

Practical Steps to Protect Your Health

Reducing your stroke risk doesn’t have to feel overwhelming. By focusing on a few key strategies, you can make meaningful changes:

Monitor Blood Pressure: High blood pressure is a silent killer. Regular check-ups and managing it with medication can reduce stroke risk by up to 40%.

Cholesterol Control: Statins lower LDL cholesterol and stabilize plaques. For those at high risk, intensive cholesterol management is life-saving.

Check for Silent Risks: Routine screenings for AFib and sleep apnoea can uncover hidden contributors.

Adopt a Healthier Lifestyle: A heart-healthy diet, regular exercise, and smoking cessation can reduce your stroke risk significantly.

Medications for Prevention: If you’ve had a TIA or are at high risk, antiplatelet drugs or anticoagulants (like aspirin or warfarin) can prevent future strokes.

A stroke doesn’t occur in isolation—it’s the result of cumulative risks over time. By understanding the causes and taking proactive steps, you can protect yourself from this life-threatening event. Early prevention, consistent health monitoring, and evidence-based interventions are your strongest allies in safeguarding your brain health.

So, take charge today. After all, when it comes to strokes, prevention is far better than cure.