What is the first step in taking blood pressure using a sphygmomanometer?

The first step in taking blood pressure using a sphygmomanometer is to inflate the cuff above the systolic pressure. This is crucial because it ensures that the cuff occludes the artery completely, allowing for an accurate reading when the pressure begins to be released. When the cuff is inflated beyond the expected systolic pressure, blood flow within the artery is temporarily stopped, which is necessary for determining both systolic and diastolic pressures.

Before this inflation, preparations may be made by placing the patient in a comfortable position, but the actual measurement begins with the inflation of the cuff. The inflation ensures that when the cuff pressure is released, the first sound of blood flow (indicative of systolic pressure) can be heard accurately.

Therefore, this action lays the essential groundwork for the subsequent steps—listening for the systolic and diastolic sounds and recording the measurements—which are vital for providing an accurate blood pressure reading.