Blood pressure (Korotkoff) sounds may be difficult to hear in some patients. An obese or muscular arm, arterial obstruction from previous surgical cutdown or atherosclerosis, or simply repeating blood pressure measurements too quickly in succession may make the readings difficult. Emptying the venous circulation in the arm helps. Have the patient elevate his or her arm above the head, and then open and close the fist several times in succession. The pressure readings will appear much more distinct on subsequent measurement.