Do you check your blood pressure in both arms? You should, according to researchers from the University of Exeter. They measured the blood pressure in both arms of 3350 healthy people, aged 50 to 70 years, with no previous history of vascular disease. After this one-off reading, the volunteers were followed for just over 8 years to see how they fared.
A different blood pressure in both arms is a warning sign
Astonishingly, over 60% of people taking part had more than a 5mmHg difference in systolic blood pressure between their two arms. What’s more, having a different blood pressure in both arms was associated with worse long-term outcomes.
Whether or not they had hypertension, those with a different blood pressure in each arm were 91% more likely to die over the 8 year follow-up period than those with no difference in blood pressure between their arms.
They weren’t just more prone to circulatory conditions such as heart attack or stroke – they were 44% more likely to die from any medical cause overall. And this was even if their blood pressure was initially in the normal range.
For those who did have hypertension at the time of BP measurement, a greater than 5mmHg difference in systolic blood pressure between both arms almost tripled their risk of dying from cardiovascular disease over the follow-up period.
Overall, there was a 2.6 fold increased risk of heart attack or stroke, rising to a three-fold increased risk for those with a greater than 10mmHg difference in systolic blood pressure between their two arms.
Why a different blood pressure in both arms is harmful
It’s now thought that a simple, one-off blood pressure measurement in both arms can help to pinpoint people with significant hardening and furring up of the arteries on one side of the body, which suggests their circulatory health is not as good as it could be.
Guidelines already suggest that doctors should measure your blood pressure in both arms when assessing you for hypertension, but this extra step is often skipped due to lack of time, lack of awareness, or a false sense of security because the reading in the first arm is fine.
If you know you have a higher blood pressure in one arm than the other, your doctor can provide more targeted treatment to reduce your long-term risks. It is even more important to ensure your blood pressure is well-controlled and that other risk factors such as a raised LDL-cholesterol or a raised glucose level are kept within the normal range.
Diet and lifestyle measures are also key – even if you don’t have pre-existing heart disease or hypertension. Eat more fruit, vegetables, oily fish and other foods good for your blood pressure. Cut back on salt, and ensure good intakes of calcium, magnesium, potassium, vitamin C and vitamin D.
So, next time you have your blood pressure measured by a healthcare professional, ask them to check the reading in both arms. It’s also a good idea to buy a home arm blood pressure monitor and keep an eye on your blood pressures yourself.