Blood pressure measurement. Doctor's hands holding a stethoscope against a patient's arm during blood pressure measurement. There is a black sphygmomanometer cuff on the patient's arm. The stethoscope is used to listen to blood flow in the arm. The cuff is inflated until it stops the flow of blood in the arm's main artery. The pressure is reduced until pulsing blood flow resumes. This pressure reading is the systolic pressure caused by the pumping heart. The cuff is then deflated until smooth blood flow resumes, giving the diastolic pressure of the heart between pumps. Abnormally high blood pressure (hypertension) can cause heart failure and kidney damage.