Blood pressure tests the amount of force that blood applies against the arterial walls. The test is measured in millimeters of mercury, or mm/Hg. Normal blood pressure readings are 120 /80 mm/Hg or less. Hypertension is considered in readings of 140/90 mm/Hg, or higher. High blood pressure causes a variety of serious complications, including stroke, heart attack and kidney failure. Medline Plus reports symptoms of high blood pressure do not exist. According to the American Heart Association, diagnosing high blood pressure involves taking two readings or more at each of two or more clinical visits.
Step 1
Remove all clothing covering the upper arm, above the elbow. Check the patient's sleeve to ensure a tourniquet effect is not occurring because a sleeve is rolled up too tight. Ask the patient to sit in a chair with legs uncrossed. Ensure that the patient is comfortably sitting with back and arm fully supported. Rest the arm about the level of the heart on a side table.
Step 2
Place the cuff, or sphygmomanometer, above the elbow so the middle of the cough is in line with the midpoint of the sternum, according to the National Guidelines Clearinghouse. The cuff placement is about 1 inch above the elbow bend. Secure the cuff. The clearinghouse recommends patients not lie down when taking a blood pressure measurement. Ask the patient to relax and avoid talking during the test.
Step 3
Place the stethoscope into your ear and the end of the stethoscope, or bell, over the brachial artery. The brachial artery is found in the inner portion of the elbow. Ensure the gauge is visible. Listen for a brachial pulse.
Step 4
Tighten the valve of the blood pressure cuff. Place two fingers over the arm's radial pulse. Inflate the cuff by pumping the attached bulb. Pump the cuff full of air until the gauge reads 30 mm/Hg above the point where the radial pulse disappears, according to the National Guideline Clearinghouse. Slowly open the valve and release the air at 2 to 3 mm/Hg per second. Listen for the first sound, known as the Korotkoff sound, or systolic blood pressure. Continue to release air as you listen for a change in sound, or the diastolic blood pressure. When the sound changes, record the number on the gauge, and release the remainder of the air. If no sounds were heard, or if you feel the reading was incorrect, wait one minute before remeasuring.
Tips and Warnings
- The National Heart, Lung and Blood Institute recommends taking two blood pressure readings, five minutes apart. If blood pressure is elevated, measure the blood pressure in the opposite arm to confirm reading. Be aware that a number of factors cause abnormal or incorrect blood pressure readings, including room temperature, nicotine, arm position, talking, bladder distention and even background noise, according to the National Guideline Clearinghouse. Never drink alcohol, coffee or smoke cigarettes within 15 minutes of having your blood pressure measured. Using the correct size blood pressure cuff ensures a more accurate reading. The National Guidelines Clearinghouse suggests the ideal cuff measure 80 percent in length and 40 percent in width of the arm circumference, or a length-to-width ratio of 2 to 1.
Things You'll Need
- Sphygmomanometer with cuff
- Stethoscope
