In manual BP measurement, the diastolic pressure is recorded when Korotkoff sounds:

• A. Are first heard
• B. Are heard continuously
• C. Disappear
• D. Are heard only with the cuff inflated

Answer: (C)

In manual BP measurement, Korotkoff sounds arise as turbulent blood flow starts to pass through an artery that is partially compressed by the cuff. When you deflate, you first hear a tapping sound as the cuff pressure drops below the systolic level, signaling the onset of systolic pressure. As deflation continues, these sounds gradually fade and eventually disappear. The pressure at which they disappear corresponds to the diastolic pressure, because once the cuff pressure falls below the diastolic level, the artery opens fully during the entire cardiac cycle and flow becomes smooth, producing no sounds. So the diastolic pressure is recorded at the point where Korotkoff sounds cease.