Hi I'm Dr. Margaret Collins-Hill with Consults in Hypertension in Wilmington, North Carolina. The question this evening is how to take a blood pressure measurement. If you've had your blood pressure measured in a doctor's office it was probably taken by someone else and they probably held a stethoscope over an artery. This takes a fair amount of training and is almost impossible to do on yourself. Fortunately now we have electronic devices that can be used at home. Most of them can be purchased at drug stores and range anywhere from $30 to $100. In general you want to avoid the wrist and finger machines because they are not quite as accurate and when you have an arm cuff you want to be sure that it fits you properly. A large arm and a small cuff will lead to an elevated blood pressure reading that you don't want. When you're taking your blood pressure there are several things you want to be sure of. First of all you don't want to have smoked for the last 30 minutes. Second of all you want to sit quietly and comfortably with your back supported in a room that's not too cold and not too hot. If someone else is in the room you shouldn't talk while you are taking your blood pressure. It's very important to hold your arm at the level of your heart if you want an accurate reading and if you're not sure how to do that think about saying the pledge of allegiance. When you place your hand over your heart hold your other arm at a level that is the same and that's the level that you want your heart to be, that you want your arm to be supported. Sometimes being seated and placing the arm on a tabletop or on the arm of a couch is at a good height. When you take your blood pressure you want to place the cuff around your arm so that the middle of the part that inflates is right over your brachial artery. Your brachial artery basically goes through the underside of your arm and then you want to place the cuff about an inch above where your arm bends. You hold your arm supported, hit the button and the cuff will inflate. The cuff will slowly deflate as the numbers are found and when it's done the numbers will appear on the display. The top number is called the systolic blood pressure and that is the pressure that's generated in your blood stream when your heart does its maximum pump. When the heart relaxes and the blood is simply pooling in the vessels waiting for the next beat that's the bottom number or the diastolic. A normal blood pressure is less than 120 on the top and less than 80 on the bottom. High blood pressure is defined as 140 on the top or 90 on the bottom. There is a lot of discussion now about what happens between 120/80 and 139/89 so stay tuned. If you have certain diseases like heart disease, stroke, kidney disease or diabetes some people need medications in this range. So to recap be sure you get a good machine, sit quietly, support your arm properly and put the cuff in the proper alignment. If you have questions, bring your machine into your doctor and have them show you how to put it on properly and while you are there have them check it for accuracy.