Blood pressure is a common concern among many of the people around the world. You can have either high or low blood pressure as early as mid-20s if you are not careful enough to watch for it. However, hypertension and hypotension normally occur during the golden part of your life. Now, you may wonder how it works to have the tendency to increase or decrease your blood pressure. There are actually many ways to do so. One is the use of a Sphygmomanometer. It is a device that measures the systolic and diastolic parts of the pressure of the blood.