High blood pressure is commonly referred to as a “silent disease,” because it typically doesn’t announce itself with any hallmark signs and has no universal symptoms. In spite of this, there are a very few symptoms that, together with warning signs in the medical history, usually make a doctor suspect high blood pressure. Among these, recurrent or worsening headache had been the closest thing to a “real” high blood pressure symptom.
It has been noted for decades that people with high blood pressure seem to suffer more frequent and severe headaches. The science and physiology behind headaches offers support to this observation, as well – increased blood pressure causes a phenomenon called autoregulation in the blood vessels that run through the tissue underneath the skull (where most headaches start). In other words, the autoregulation leads to constriction of these blood vessels, a very well known cause of headache symptoms.
Emerging research from Norway, though, hints that people with high blood pressure may actually have fewer headaches than those with normal blood pressure. The studies, conducted in Norwegian patients and published in a large medical journal in the United States, were designed as a follow up to earlier research and found that people with elevated, untreated high blood pressure were as much as 50% less likely to suffer a headache than were patients with similar health profiles but normal blood pressure.
Among participants in the study, those with higher systolic pressures and wider pulse pressures seemed to be the most protected from headache. Interestingly, patients with high blood pressure who were receiving treatment seemed to have headache risk similar to that of patients with normal blood pressure. This treatment/headache risk relationship persisted even in patients who continued to have some elevation in their blood pressure readings despite treatment. This suggests that headache risk may rise as blood pressure falls.
Researchers don’t yet know why elevated blood pressure protects against headaches. Theories range from altered levels of certain hormones and blood chemicals to differences in artery stiffness – arteries tend to become more stiff as blood pressure rises, one of the main reasons that high blood pressure can lead to blood vessel damage.
While this may be a small piece of good news for those suffering from high blood pressure, the risks of elevated blood pressure still far outweigh any associated headache reduction benefits. If you are being treated for high blood pressure and are suffering from frequent or severe headaches, you should not stop taking your medicines. Rather, you might require a different medicine and should speak with your doctor.
Tronvik E, Stovner LJ, Hagen K, Holmen J, Zwart JA. High pulse pressure protects against headache: prospective and cross-sectional data (HUNT study). Neurology. 2008 Apr 15;70(16):1329-36.