Blood Pressure Test

Blood Pressure Test

What is a Blood Pressure test? Throughout your body, your heart pumps blood through blood vessels.  The heart can pump the blood fast and slow.  For example, think about a garden hose.  If the water is just trickling out, the water is moving slow and at a low force, but if you turn on the hose all the way, the water shoots out really fast and at a high force.  This is how your blood vessels work; your heart can pump blood through the vessels slow or fast.  To measure how your blood is moving around your body, the blood pressure test is used. A blood pressure test (sphygmomanometer) measures the force (how fast or slow) of the blood moving through your blood vessels.  You may remember hearing numbers when nurses and doctors are talking about your blood pressure.  For example you may hear 120 over 80.  The first number 120 means how fast your blood is being pushed out of your heart and into the blood vessels, this is called systolic.  The other number 80 means this is how fast your blood is going back to your heart, this is called diastolic.  A blood pressure test measures both how fast your blood is being pushed out of your heart and how fast your blood is going back to your heart. Why do I need to have a Blood Pressure test? Usually when you are in the hospital, your blood pressure is checked everyday, sometimes it can even be checked a few times a day.  This just lets the doctor and nurse know how your blood is moving around your body. What does a Blood Pressure machine look like? The blood pressure machine has a small computer and a blood pressure cuff.  The cuff is made of material with some Velcro on it.  The cuff is attached to the computer by a rubber cord.  It is on a cart or a small pole so that the nurses can move it around from room to room, or sometimes it is attached to the wall in your room.   No picture is taken, just the numbers show up on the small computer screen for the nurses to write down and tell the doctor. Sometimes the nurse will use a blood pressure cuff that is not attached to a computer.  When the nurse uses this type of blood pressure cuff, they use a pump to pump air into the cuff to fill it with air and read the numbers from the side of the cuff where the pump is. What happens when I have a Blood Pressure test? A nurse will come to you with the blood pressure machine.   She may ask you to roll up your sleeve.  She will then place the cuff around your arm, just above your elbow.  Sometimes the nurses may put the cuff on part of your leg.  The nurse will then attach the Velcro to make sure it says in place.  A button will then be pushed on the machine, and the cuff will start to fill with air.  If the blood pressure cuff is not one that connects to a computer, then the nurse will use a pump on the side of the cuff to help the cuff fill with air.  Once it has filled, you will notice that the cuff is very puffy and gives your arm a tight hug/squeeze.  The machine will beep that it is done and the nurse will remove the cuff from your arm. What will the Blood Pressure test feel like? The nurse will wrap a small cuff around a part of your arm or your leg.  When the machine is on, the cuff fills with air.  The cuff will get snug (tight) around your arm or leg.  Do not worry, the cuff will stop filling with air when it is done, and the air will be let out of the cuff.  It is important to relax and stay still so that the test will be short.  If you move your arm or leg around, the test will take longer which means the snug cuff will be on your arm or leg longer.  The test should take less then a few minutes and will be done a few times a day, sometimes even at night.  Sometimes it can help to think of something else, like your favourite place or song, while having the blood pressure done.  Other ideas to try to help you lie still are quiet activities like blowing bubbles or watching your favourite movie. Preparing for the test There is nothing that you need to do to prepare for a blood pressure test.  You do not have to go anywhere to have the test done; your nurse will come into your room with the machine and check it for you. Remember If you have any questions about the test, always ask!

This content has been reviewed and approved by health care team members at McMaster Children's Hospital in Hamilton, Ontario.