Migraines and Strokes: Is There a Link?

Migraines and Strokes: Is There a Link? 

Strokes are the second most common cause of death worldwide. They are typically caused either by a disruption in blood flow to the brain (an ischemic stroke) or by bleeding in the brain (a hemorrhagic stroke). Symptoms can vary widely depending on the part of the brain affected. One thing is clear, however: a stroke is always a medical emergency that requires immediate treatment in a hospital.

In recent years, researchers have noticed a worrying trend: more and more young people are having strokes. This is puzzling, because most strokes can be traced back to ‘traditional’ risk factors like high blood pressure, obesity, smoking, type 2 diabetes, high cholesterol, or heart disease, which are common in older adults. But in younger people, those risk factors often don’t apply.

New studies point to migraine as a possible risk factor

One area now drawing attention in research is migraine. A major study published in spring 2024 helped shine a light on this. At a university in Colorado, over 2600 patients who had experienced a stroke were examined, along with a control group of about 8000 people with no history of stroke. All participants were between 18 and 55 years old. The research was based on long-term observations showing a steady increase in stroke cases among people under 55 in high-income countries. Until recently, most research had focused on traditional risk factors and their effects on blood vessels in the brain. This approach does not fully explain why even seemingly healthy young people are having strokes, however. What’s also striking is that in this age group, the rates of heart attacks and sudden cardiac death have been going down. That’s important, because those conditions share many of the same traditional risk factors as stroke – so why would strokes be going up?

Large-scale studies from the Netherlands and the U.S. have shown that women under 45 face a significantly higher risk of stroke compared to men. But when it comes to heart attacks, it’s the opposite: men between 35 and 45 have twice as many heart attacks than women. This contradiction has pushed researchers to reevaluate old assumptions and take a closer look at ‘non-traditional’ risk factors – including migraine.

Intriguing: risk factors vary by age group

In the Colorado study, researchers sorted health data by age group to get a clearer picture.

Among 18–34 year olds, cardiovascular diseases – high blood pressure in particular – were among the top stroke risk factors for both genders. But one surprising result stood out: migraine emerged as a more significant risk factor than high blood pressure.

The same held true for participants aged 35–44. In women, heart disease and hormonal factors also played a role in increasing stroke risk. However, even in this group, migraine remained one of the strongest predictors, along with high blood pressure.

In the 45–55 age group, additional risks like diabetes, smoking, alcohol use, and kidney disease came into play – especially for men. But regardless of gender, migraine was again the most important non-traditional risk factor.

Overall, the data showed that traditional and non-traditional risk factors carry roughly equal weight when it comes to stroke.

Put simply: the older the person, the more traditional risk factors matter; the younger the person, the more non-traditional ones come into play. For people under 35, conditions like migraine, blood clotting disorders, autoimmune diseases, or kidney problems have a major impact. For those over 45, it’s more often the usual suspects: high blood pressure, high cholesterol, obesity, and lack of exercise.

The tricky question of cause

It now seems clear that people with migraine face a higher risk of stroke. But identifying a statistical link is only the beginning: figuring out why that link exists is far more complex. Could migraine itself – and its effects – increase stroke risk? Are there genetic factors that both conditions share? Do the two diseases develop in similar ways? Researchers have explored these questions and found several factors that might help explain the connection. Much remains uncertain, however.

What is clear: the link between stroke and migraine is especially strong in women aged 18–34. This is important, because migraine is also much more common in women than in men. Could that help explain the risk?

A closer look at blood vessels

One focus in the search for answers is the blood vessels themselves. In people under 55 who experience strokes, researchers have found that the number and function of key blood vessel cells are often reduced. These cells are essential for keeping vessel walls stable. Without them, blood vessels can become fragile and more likely to rupture. This vulnerability increases even more when high blood pressure is present — a condition that is more common in migraine sufferers than in the general population. On top of that, the brain’s blood vessels in people with migraine tend to be more sensitive to spasms. These vasospasms can dangerously narrow the blood vessels and reduce blood flow to the brain. The resulting pressure can even cause blood vessels to burst.    

Another risk comes from faulty blood platelets – the cells responsible for clotting, for example to stop bleeding if you cut yourself. In some cases, these cells clump together abnormally, forming clot-like masses (called thrombi) that can block small blood vessels. This either cuts off blood supply to brain tissue, or increases pressure so much that weakened vessel walls rupture – potentially causing serious damage in the affected area of the brain.

Migraine attacks themselves can pose a threat

A migraine attack isn’t just painful. It also puts major stress on the brain. During an attack, something called ‘cortical spreading depression’ occurs: a wave-like disturbance involving countless nerve cells that spreads gradually across the brain’s outer layer (the cerebral cortex). This is what triggers migraine pain. It also temporarily reduces blood flow in the affected regions. In severe or prolonged attacks, or in people with a genetic predisposition, this can lead to lasting damage and all the signs and symptoms of a stroke.

The role of hormones

For women with migraine, hormonal birth control pills are a known risk factor. Even without additional factors, women already have a higher stroke risk than men. But with hormonal contraceptives, that risk increases significantly. One study commissioned by the World Health Organization (WHO) found that hormonal birth control increases stroke risk by a factor of 8 in women with migraines, compared to those who don’t use this kind of birth control. Other studies also found increased risk from hormone replacement therapy used to ease menopause symptoms. So it’s clear: hormonal influences play a major role in stroke risk.

Knowledge is key to prevention

The connection between migraine and stroke is complex. Many different risk factors seem to interact in different ways, and both age and gender play a role. Although science hasn’t yet uncovered a complete explanation, research is moving forward, and that’s good news.

The more we understand, the more people can learn to manage their personal risk, ideally with the help of a healthcare provider. Regardless of the migraine-stroke connection, managing migraine effectively can make a huge difference in your quality of life. Targeted migraine prevention has proven benefits. Studies show that people who learn to understand their personal migraine patterns and take preventive steps often see a clear reduction in the frequency and severity of their attacks.