High blood pressure is just what it sounds like – your blood is moving through your blood vessels at a higher pressure than normal. Of course, your blood pressure is constantly changing due to a variety of factors, but we’re talking about a higher pressure than is normal under the circumstances, or generally higher than normal.
In 1913 Dr. Theodore C. Janeway suggested a link between high blood pressure and headache. Many of Janeway’s theories are still generally accepted today – but the hypertension headache connection is under suspicion.
I should put it this way – it’s generally accepted that hypertension in most cases doesn’t cause headache. In fact, it’s more likely to be the other way around.
In fact, this past spring a study in Norway (published in the 15 April edition of Neurology) suggested that high blood pressure is linked to fewer headaches, and even migraine attacks!
It seems more clear that headaches could cause high blood pressure. First, pain itself can cause temporary high blood pressure. That’s usually not considered dangerous, and it goes away (in other words, chronic pain is not likely to cause long-term high blood pressure).
Second, many medications taken for headache can cause high blood pressure. Long term use of anti-inflammatory drugs can cause hypertension. This would include ibuprofen (ie Advil) and naproxen (Naprosyn).
But wait – aren’t some drugs for hypertension also used to treat migraine? Yes, there are preventative drugs for migraine that are also used for hypertension, such as calcium channel blockers and beta blockers (such as Atenolol (Tenormin)). However, the reason these work for migraine is not the same reason they work for high blood pressure.
In 2005, British researchers fought back and suggested that hypertension does cause headache. This was a meta-study, studying the data from other studies. However, there are reasons why this probably isn’t the last word.
For example, the study showed that people on medication for hypertension had fewer headaches. That shouldn’t be a surprise, but it’s a long way from proving that hypertension is causing headache. Also, these weren’t studies designed to find out if high blood pressure causes headache – they were focused on other things. Studies focused on the question are still inconclusive after almost 100 years. (more on this study)
Drs Young and Silberstein sum it up well in their book Migraine and Other Headaches:
In order for high blood pressure to cause a headache, it has to be so high that it overcomes the normal protective reflex of the brain’s blood vessels … Blood pressure so high that it causes a headache is a medical emergency. Some people may have high, but not immediately dangerous, blood pressure due to pain caused by a headache.
Is high blood pressure causing my headache? Probably not. But do be cautious of taking medications that could increase blood pressure, especially if your doctor is already concerned about your blood pressure.