Researchers are working to fully understand the link between high blood pressure and migraine; it’s unclear whether one causes the other, or whether there is another factor that may cause them both. Whatever the case, it’s important for anyone with high blood pressure to get it under control, and that’s especially true for people with other risk factors for heart disease, including migraine. “Individuals with migraine are at higher risk overall of cardiovascular disease, particularly stroke, so for that reason, it’s important for people with migraine to manage other risk factors, including hypertension,” says Pamela Rist, ScD, an assistant professor at Harvard Medical School and the Harvard T.H. Chan School of Public Health and an associate epidemiologist at Brigham and Women’s Hospital in Boston. RELATED: What You Need to Know About Migraine and Heart Disease

Women are three times more likely than men to have migraine, according to the Migraine Research Foundation, and for this reason, much of the research on the link between hypertension and migraine has been conducted on women. According to Dr. Rist, “it’s difficult to untangle the two conditions, and to do so, we need to look at it from so many different angles. It appears that there is a genetic trait linked with both, but some believe it’s a causal relationship,” meaning that either migraine causes high blood pressure or vice versa. In a study examining the potential causal relationship, published in February 2018 in the journal Cephalalgia, researchers followed nearly 30,000 women for 12 years. They found that, overall, women who had a history of any type of migraine were more likely to have high blood pressure than women who did not have a history of migraine. In addition, some types of migraine appeared to be correlated with higher rates of hypertension than others. Compared with women with no history of migraine, those who had a history of migraine without aura had a 21 percent increased risk of hypertension — twice that of women who had migraine with aura, whose risk was elevated by roughly 10 percent. A study looking for a genetic explanation, published on July 6, 2020, in Nature Communications, identified 12 genes that appeared to have an impact on both blood pressure and susceptibility to migraine. The research supported previous observations that the major types of migraine, migraine with aura and migraine without aura, were associated with higher systolic pressure, which is a measure of the force exerted when your heart contracts and is the first number in a blood pressure reading, as well as diastolic blood pressure, or the force exerted between beats and the second number in a blood pressure reading. The link was strongest between elevated diastolic blood pressure and increased susceptibility to migraine.

Can a Migraine Cause High Blood Pressure?

During migraine attacks, some people report elevated blood pressure, which may be part of an autonomic response to pain, says Teshamae Monteith, MD, the chief of the headache division at the University of Miami Miller School of Medicine in Florida, who is also on the editorial board of the American Migraine Foundation. “People may not have blood pressure problems between migraine attacks, but when migraine attacks are frequent, blood pressure abnormalities become more concerning,” Dr. Monteith says, noting that in such cases, a doctor may prescribe hypertension medications such as beta-blockers to help prevent migraine attacks. In other cases, headache accompanied by high blood pressure can sometimes be a sign of another underlying condition, says Monteith. This can be particularly true in cases of supine hypertension, in which a person’s blood pressure rises when they lie down. People with sleep apnea may also experience both migraine and hypertension in the morning, and rare conditions such as pheochromocytoma, or tumors in the endocrine system, can also cause high blood pressure alongside intermittent headaches, she says.

What Does a Headache Feel Like With High Blood Pressure?

According to the American Heart Association (AHA), a headache can be a sign that a person is experiencing a hypertensive crisis, meaning blood pressure reaches 180/120 millimeters of mercury (mmHg) or higher, which is a medical emergency if it does not quickly lower. Anyone who experiences blood pressure this high and has a headache or nosebleed should see a doctor immediately, the AHA notes. When systolic blood pressure is greater than 180, headache can occur along with confusion and visual changes, adds Monteith. “Any secondary warning signs could be a sign of something much worse,” she says. These signs include vision loss, weakness, vertigo, trouble with balance, or change in speech. Pregnant women should be keenly aware of any warning sign that may indicate high blood pressure, including migraine. “Headaches and severe hypertension can sometimes be signs of a stroke, so getting to the emergency room immediately, especially if neurological symptoms develop, is critical,” says Monteith.