Blood pressure measurement should be the same in both arms since the heart pumps the blood to all places at the same pressure. It is common for people to have a bit of difference in blood pressure between the right and left arms because we don’t take the blood pressure in both arms at the same time. Blood pressure and heart rate varies with activity and sometimes with anxiety. This is one of the reasons that doctors often take the blood pressure at the beginning and at the end of the examination.
If your blood pressure is always higher in one arm than the other, this may mean that there is an impediment to flow through the blood vessel that has the lower pressure. It is important for you and your health care provider to know if you do have a difference in blood pressure between your arms, as the blood pressure that is being treated should always be the one taken on the higher side.
Sometimes the blood pressure is much lower on one side and this can cause problems with the blood flow with arm fatigue, arm discomfort on doing things like washing the dishes, and coldness to the hand. In addition, because the arm needs adequate blood supply, in a small number of cases the body reroutes the blood down through an artery in the back of the neck stealing blood from the brain and causing dizziness and rarely loss of consciousness with the use of the arm. This is called subclavian steal syndrome. When the blood flow to the arm and/or brain causes significant problems it can often be corrected therefore any problems should be reported to your doctor.
Important: We hope you find this general medical and health information useful, but this Q&A is meant to support not replace the professional medical advice you receive from your doctor. For all personal medical and health matters, including decisions about diagnoses, medications and other treatment options, you should always consult your doctor. See full Disclaimer.
Larry Weinrauch is a cardiologist in Watertown, Massachusetts and is affiliated with Mount Auburn Hospital. He wrote for HealthCentral as a health professional for Heart Health, High Blood Pressure, and High Cholesterol.