Stroke: About Stroke

About the Condition

How Common is Stroke?

Stroke is the fourth leading cause of death and one of the leading causes of adult disability in Singapore (MOH, 2024). While age and chronic diseases like high blood pressure and diabetes are major risk factors for stroke, the incidence of stroke among younger adults below 50 years of age has significantly increased (NRDO, 2025).

Learn more about the impacts and complications of stroke in the linked articles.

Types of Stroke

There are 2 main types of stroke: ischaemic and haemorrhagic. Transient ischaemic attacks (TIA) cause similar symptoms to stroke and may be a warning sign of future stroke.

Ischaemic Stroke

This is the most common type of stroke, accounting for about 80% of strokes in Singapore (NRDO, 2025). It occurs when a blood clot is lodged in an artery in the brain, cutting off blood supply and causing brain cells to die as they cannot get oxygen and nutrients. There are two main types of ischaemic stroke:

Embolism

A blood clot, usually from the heart or a narrowed blood vessel, gets dislodged and travels to the brain through the bloodstream. Clots can form due to pre-existing conditions like uncontrolled atrial fibrillation.

Thrombosis

A blood clot forms locally in a brain artery, usually due to underlying narrowing of the vessel from fatty plaque formation on the vessel walls. As the vessel is narrowed, it is more easily blocked. This buildup of fatty plaque is called atherosclerosis, which can develop as a result of unmanaged high blood pressure (hypertension), high blood cholesterol (hyperlipidaemia), diabetes, and unhealthy lifestyle habits like smoking.

Ischaemic strokes can be treated through intravenous (IV) medication and endovascular therapy. Learn more about how stroke is managed here.

Haemorrhagic Stroke

This type of stroke is less common, accounting for the remaining 20% of strokes in Singapore. Haemorrhagic strokes occur when a blood vessel in the brain ruptures, causing blood to leak into the brain. Brain cells die as they cannot get oxygen and nutrients. Additionally, pressure builds up in the skull because of the blood and inflammation of surrounding tissue, creating a life-threatening situation. These strokes are usually caused by uncontrolled high blood pressure or ruptured aneurysms, which are weak spots on the vessel wall that bulge out. 

There are two main types of haemorrhagic stroke:

Intracerebral Haemorrhage (ICH)

The bleed occurs within the brain, creating pressure on the brain from the inside. ICH is the most common type of haemorrhagic stroke.

Subarachnoid haemorrhage (SAH)

The brain is surrounded by a layer of tissue called the arachnoid membrane. If a blood vessel in the arachnoid membrane or one on the surface of the brain bursts, blood can pool in between the brain and the membrane. This creates pressure on the brain from the outside.

Haemorrhagic strokes carry a higher risk of death and disability than ischaemic strokes. They can possibly be treated with blood pressure measurement and surgery. Learn more about how stroke is managed here.

Transient Ischaemic Attack

TIAs occur when there is a temporary interruption of blood supply to the brain, causing stroke-like symptoms that resolve completely. The causes and symptoms of a TIA are similar to that of a stroke (F.A.S.), but they do not cause permanent brain damage.

TIAs must be taken seriously. Even though the symptoms resolve without treatment, they are often a warning sign of a future major stroke. 10-15% of TIA sufferers have a stroke within three months of their TIA, and half of these strokes occur within 48 hours from the onset of TIA symptoms (Loh et al., 2016).

Silent Stroke

A silent stroke is a stroke that does not present with any outward symptoms but still causes brain damage. The patient is often unaware that they have had a stroke and only find out after brain imaging. These strokes increase the risk of future strokes and TIA.

Silent strokes often impact regions of the brain that do not cause noticeable changes in movement of appearance. The risk factors for silent stroke are similar to that of other kinds of stroke, so it is important to manage your health consistently to reduce your risk for stroke.

All types of stroke and TIAs are medical emergencies; if you notice any symptoms, call 995 immediately instead of going to a family doctor of polyclinic.

About the Brain

Strokes can occur anywhere in the brain. The damage and effects of stroke depend on which part of the brain is affected and how long it progresses without treatment. Brain scans may reveal the type and location of stroke.

The brain can be divided into two halves (hemispheres). Generally, the left half of the brain controls the right half of the body, and the right half of the brain controls the left half of the body.

The brain can also be divided into these regions. Each region has specific functions and the different parts of the brain also work together to control thoughts and behaviours.

Causes and Risk Factors

Uncontrolled chronic illnesses like high blood pressure (hypertension), high blood cholesterol (hyperlipidaemia), diabetes, and atrial fibrillation, as well as poor lifestyle choices like smoking are risk factors for stroke. Read more about these risk factors and how to manage your risk for stroke here. 

Signs and Symptoms

Stroke is a medical emergency. Early intervention can lower the extent of brain damage and disability. One way to identify stroke is to use the acronym F.A.S.T. If you see any of these signs, call 995 immediately. Learn more about the signs and symptoms of stroke here. 

Common Misconceptions About Stroke

1. When I see someone with signs of stroke, I should tell them to go see their GP.

If you see any one of F, A, or S, call 995 immediately. They could be experiencing a stroke, which is a medical emergency. Time is Brain: the faster someone receives treatment, the less damage can be done to their brain.

2. Someone who is only experiencing speech difficulty without face weakness or arm drift cannot be having a stroke.

Call 995 even if only one symptom is present. Having any one sign may still indicate a stroke. Not all three signs need to be present for it to be a stroke.

3. Only the elderly have strokes.

Anyone at any age can have a stroke. Young people may also suffer from strokes.

4. Strokes cannot be prevented. If they happen, they happen.

About 80% of strokes are preventable by managing risk factors like high blood pressure (hypertension), high blood cholesterol (hyperlipidaemia), diabetes, and making lifestyle chances like quitting smoking, exercising regularly, and maintaining a healthy diet.

5. Once you have a stroke, nothing can be done.

Rapid treatment and rehabilitation after hospitalisation can greatly improve functional outcomes after stroke. This is why it is crucial to call 995 immediately after noticing any sign of stroke.

References

MOH (2024). Principal Causes of Death. www.moh.gov.sg/others/resources-and-statistics/principal-causes-of-death/

NRDO (2025). Singapore Stroke Registry Annual Report 2022. www.nrdo.gov.sg/publications/stroke

Loh, V. W. K., Soon, D. T. L., & Yeo, L. L. L. (2016). Outpatient management of transient ischaemic attack. Singapore Medical Journal, 57(12), 658-664. DOI: 10.11622/smedj.2016190