Research shows that biological sex (and perhaps also gender) can impact stroke risk.

Generally, males tend to have a higher risk of stroke at younger ages. But females have a higher lifetime risk of stroke because they tend to live longer¹.

Note that most of the published data on stroke have not explicitly separated sex and gender and likely incorporate both influences². Sex refers to biological characteristics such as genetics including features that define our appearance (for example height or colour of our skin). Gender refers to identity, expression, roles and stereotypes for female, male and gender diverse people.

Stroke risk in females

Females are more likely to have a subarachnoid haemorrhage (a bleed in the space between the brain and the surrounding membrane)¹.

Research also shows that in females, the risk of an ischaemic stroke (caused by a blockage to the blood supply in the brain) begins rising at lower blood sugar levels³. There may also be a stronger link between high blood pressure and stroke in females.

Some factors may specifically affect females’ stroke risk:^1,4

• Preeclampsia and gestational diabetes during pregnancy can increase stroke risk both during pregnancy and later in life⁵. Therefore, those with a history of gestational diabetes and previous stroke may be given metformin to control blood sugar⁶.
• Some studies suggest that hormone replacement therapy, and particularly oestrogen-only therapy, may increase stroke risk in post-menopausal females, especially those who start treatment later in life.
• Females who experience migraines with aura may have a slightly higher stroke risk.
• Oral contraceptives, especially those containing oestrogen, may slightly increase stroke risk. This is particularly true in people who have other risk factors, such as smoking, high blood pressure or being over 35 years old⁷.

Stroke risk in males

On average men have a higher risk of strokes than women although they tend to have strokes at a younger age and have higher rates of haemorrhagic stroke (which is caused by brain bleeds).

Men are more likely to be smokers; they have a higher incidence of atrial fibrillation and an increased risk for stroke related to hyperlipidaemia (high fats including cholesterol). Some men have sex-specific risks related to low testosterone levels^1,4.

Stroke risk in transgender and gender diverse people

Research with gender diverse people who do and do not take hormones is still in its infancy. There is some evidence that taking oestrogen raises stroke risk in this population⁸. Therefore, those taking oestrogen for gender affirmation should ensure other risk factors are under control (e.g., through lifestyle modifications and managing medical conditions) to reduce associated stroke risk⁷.

Gender, biological sex and stroke: Key points

Stroke is a leading cause of death for males and more likely to occur at younger ages.

However, females have an array of specific risk factors, from longer lifespans to pregnancy complications, that mean they carry a bigger burden of disability related to stroke.

No matter what our sex or gender is, it is critical to be aware of our stroke risk and take steps to lower your risk. Physical activity, drinking less alcohol and managing certain medical conditions can help prevent strokes.