Blood pressure is an integral measure of your health. If your blood pressure is too high, your veins and arteries are under increased pressure, which can lead to cardiovasular disease. If your blood pressure is much too low, your heart may not pump enough blood to your head and extremities, leading to slightly numb hands and lightheadedness. It is important to keep track of your blood pressure to prevent these symptoms, and this can be done using a blood pressure machine. Depending on the machine type, you will either wrap a part of the machine around your upper arm an inch above your elbow, or put your arm into the machine. The machine will the put pressure on your arm and slowly release, and then determine your blood pressure. If you find your blood pressure is reported as very high or low, you should consult a doctor for further examination.