Final answer:
For blood pressure measurements, either arm can be used, but the arm with the higher readings is usually preferred for consistency.
Step-by-step explanation:
In general, either arm can be used for blood pressure measurements, but comparing readings from both arms can be useful in detecting any differences that might indicate health issues such as vascular disease. For the most consistent and accurate readings, healthcare providers typically recommend using the arm that has the higher readings and then consistently using the same arm for future blood pressure measurements. The method of measurement involves an inflatable cuff placed on the upper arm at heart level and using a mercury manometer to read the pressure.
Consistency in the measurement technique is key. When the cuff is inflated, it temporarily halts blood flow, and as it deflates, blood flow resumes, allowing the measurement of systolic and diastolic pressures. If the arm is above the level of the heart, for example, the measurements could be artificially low, due to the effects of gravity on the circulatory system.
Therefore, to ensure accurate readings, healthcare providers always follow a standardized procedure.