Blood pressure is measured in your arm and represents the effect in your blood vessels of the squeeze phase or systolic and relaxing phase or diastolic of your heart. The systolic is the first or top number of a blood pressure measurement. And this diastolic is the second or bottom number. Most experts agree that your systolic blood pressure should be between 100 and 130. And your diastolic pressure should be between 60 and 80. If you came to the ER because of high blood pressure, though, your pressure may have been 200 over 100 or even higher than that. This can seem scary to be so high, but you want to make sure that pressure does not correct too quickly. Your emergency physician probably tried to decrease your blood pressure by 10 to 20% in a single visit and advised you to follow up with a primary physician or specialist blood pressure control takes time. You and your doctor have to work on a good target.