Your blood pressure is one of the best indicators of your overall health as your heart beats, it pumps blood through your blood vessels and a pressure wave called a pulse. Your blood pressure reading uses 2 numbers, for example 120 / 80 to measure the force that this wave exerts against the walls of your arteries. Blood pressure is measured with a stethoscope and an inflatable cuff and pressure gauge called a sphygmomanometer. When the cuff is inflated, it squeezes in on your arm, closing off the arm's main artery and stopping the flow of blood. A person listening through the stethoscope won't hear any sound when the blood is stopped. When the cuff is slowly deflated, blood once again pushes through the constricted portion of the artery, causing the artery to vibrate and produce sound. A person listening through the stethoscope will now hear a soft pulsing begin. The point at which this sound can first be heard, represents the first number in your blood pressure reading called the systolic pressure. This is the pressure exerted when your heart muscles contract. As the cuff continues to deflate, the narrow portion of the artery gradually widens, allowing more blood to flow. When the cuff no longer pinches the artery, the soft pulsing stops the point where the sounds become muffled or can no longer be heard at all. Is the second number in your blood pressure.