What is the expected difference in systolic blood pressure between the thigh and arm?

The expected difference in systolic blood pressure between the thigh and arm is typically 20-30 mm Hg. This variation is primarily due to the anatomy and physiology of the vascular system. The thigh contains larger arteries, such as the femoral artery, which can yield higher systolic pressures compared to the smaller arms. This difference is often used as a clinical indicator, particularly in evaluating conditions like coarctation of the aorta, where blood flow is compromised in certain areas.

A difference of 20-30 mm Hg signifies a normal physiological variance and helps healthcare providers assess vascular health. A slightly lower difference might indicate more normal anatomy but can also signal potential cardiovascular concerns if the difference is significantly less or greater than this expected range. Understanding this variation is crucial for accurate blood pressure assessments and the overall evaluation of a patient’s circulatory status.