MODEL RELEASED. Blood pressure measurement. General practice doctor measuring a woman's blood pressure with a sphygmomanometer, its pressure gauge seen at centre right. The patient has an inflatable cuff (black, centre) on her arm and a stethoscope is pressed against the patient's arm to listen to blood flow. Blood pressure is an important measure of health and fitness. An average reading for a healthy young adult at rest is 120/80 millimetres of mercury. Abnormally high pressure (hypertension) can cause heart failure or kidney damage.