Can high blood pressure cause headaches?
The answer is yes and no.
The relationship between high blood pressure and headaches has been studied extensively in medical research. There are several findings that link high blood pressure to headaches. However, except in two specific situations, headaches are not thought to be caused directly by high blood pressure.
I have treated thousands of patients with high blood pressure and headaches and have had experiences with both scenarios:
- Headaches caused by high blood pressure
- High blood pressure and headaches at the same time without one causing the other
I will be sharing my experience as well as a review of medical literature that explores the relationship between high blood pressure and headaches. I will be breaking down the information into plain English without skipping any important details.
Headaches caused directly by high blood pressure
There are two different situations where headaches are caused directly by high blood pressure:
- Headaches caused by dangerously high blood pressure
- Headaches caused by bleeding inside the brain from dangerously high blood pressure
Headaches caused by dangerously high blood pressure
When is blood pressure dangerously high?
Traditionally, dangerously high blood pressure has been defined as blood pressure higher than certain arbitrarily chosen numbers: 180/120. The upper number or systolic pressure has to be higher than 200 or the lower number or diastolic pressure higher than 120. These numbers were chosen before evidence-based medicine became mainstream. These numbers have not been specifically tested in any scientific trials.
However, whenever blood pressure is higher than that, patients usually have headaches and the consensus is that the headaches in those situations are caused by the dangerously high blood pressure.
In my personal experience, the higher the blood pressure, the higher the chances of patients having symptoms of bad headaches. Normally, when I see someone with blood pressure higher than 210/120, they almost always have headaches. Blood pressure of 210/120 is where most doctors get really worried and start urgent intervention with ICU monitoring.
Headaches associated with bleeding inside the brain from dangerously high blood pressure
Dangerously high blood pressure can burst open blood vessels inside the brain, resulting in the brain bleeding. Patients with such brain bleed have extremely bad headaches. In fact, whenever someone comes to the ER with dangerously high blood pressure and headaches, brain bleed is the first thing we are concerned about. Anyone in a similar situation needs a head CT right away looking for possible brain bleed.
High blood pressure and headaches at the same time without one causing the other
There have been numerous other studies trying to find links between other types of headaches and high blood pressures. However, none of them have consistently proven direct links. Here are some interesting findings about the relationship between high blood pressure and migraine headaches.
A study comparing high blood pressure patients with headaches and high blood pressure patients without headaches
Some patients with high blood pressure have headaches and others don’t. This study wanted to see if having both high blood pressure and headaches is worse than high blood pressure without headaches. They wanted to see if perhaps headaches associated with high blood pressure meant that those high blood pressure patients had a worse kind of high blood pressure. This study was published in the American Journal of Hypertension in 2016. They followed 1,914 patients for 30 years. They initially marked them as having high blood pressure with headaches and high blood pressure without headaches. At the end of the 30 years, they tracked those patients and found out that 580 of them died from a heart attack and 97 of them died from a stroke.
When they analyzed the data, they were surprised to find that more people who died from heart attacks did not have headaches with their high blood pressure. In other words, having a headache along with high blood pressure somehow made them less likely to die from a heart attack. When they looked at number of people who died from a stroke, there was no significant difference between the two groups. This study seem to suggest that having high blood pressure and headaches was not worse than having high blood pressure without headaches.
A study comparing the blood pressures of patients visiting the emergency department with headaches to the blood pressures of patients visiting the emergency department without headaches
This study was published in the American Journal of Emergency Medicine in 2014. They looked at 2 different groups of randomly assigned patients. The first group consisted of patients who visited the ER with complaints of headaches. The second group visited the ER with any complaints other than headaches. They eventually reviewed all the charts of those patients and compared their blood pressures. They found out that the blood pressure of those who came in with headaches was higher than that of those who came in with other symptoms. This study suggested that if you visited the ER with a headache, you are more likely to have a higher blood pressure than if you visited the ER without headaches. However, it did not mean that you were more likely to have headaches with higher blood pressure.
They took it one step further and reviewed their blood pressure after their headaches improved with medication. They found out that treating the headaches did not significantly lower their blood pressures.
A study comparing the association between high blood pressure and migraine headaches in patients visiting the ER in northern Manhattan
This research named “Hypertension and Migraine in the Northern Manhattan Study” looked at 1,338 patients who visited the emergency department. They were evaluated for migraine headaches and high blood pressure. The results were analyzed. They found that patients with high blood pressures were more likely to also have migraines compared to the patients who did not have high blood pressures. This study showed some significant association between high blood pressures and migraine headaches. But not all migraine headache patients had high blood pressure and not all high blood pressure patients had migraine headaches.
In conclusion, there seems to be some relationship between high blood pressures and headaches, but except in the two situations I outlined in the beginning of the article, it seems unlikely that high blood pressure directly causes headaches. I hope that this article answered some of your questions about high blood pressure and headaches.
References:
https://academic.oup.com/ajh/article/29/9/1109/2622261
https://www.ajemjournal.com/article/S0735-6757(14)00336-2/fulltext