To check your blood pressure you have to use a blood pressure machine. You can have this done for you at your doctor’s office. Some drug or grocery stores will have a machine. You can also buy small blood pressure units to use at home. You will pull the cuff up over your arm and turn the machine on. It will pump up the cuff, putting pressure on your arm. The machine will record your body’s reaction to that pressure by as it relaxes and give you a reading.