The Normal Blood Pressure

Abel Goa, Saturday, November 17, 2012

Classification of Blood Pressure for Adults, 18 years of age and older

The optimal blood pressure is < 120 mm Hg systolic and <80 mm Hg diastolic The normal blood pressure is <130 mm Hg systolic and <85 mm Hg diastolic Hypertension: Mild is 140 – 159 mm Hg systolic and 90 – 99 mm Hg  diastolic Moderate 160 – 179 mm Hg systolic and 100 – 109 mm Hg diastolic Severe ≥ 180 mm Hg systolic and ≥ 110 mm Hg Diastolic

                                                                                    From: SAM-CD connected; Scientific America, 2002.

Blood pressure is the tension of the blood within the systemic arteries, maintained by the contraction of the left ventricle, the resistance of the arterioles and capillaries’, the elasticity of the arterial walls, as well as the viscosity and volume of the blood; expressed as relative to the ambient atmospheric pressure. Blood pressure normally rises as you age and grow.

Experts consider the normal blood pressure to be less than 120/80 mm Hg. At one point, blood pressure at or above 120/80 and less than 140/90 was considered normal to high; these numbers are now considered pre – hypertensive.

Normal blood pressure readings for children are lower than for adults, while blood pressure for adult and teenagers are similar.

In children height has a significant effect; taller kids have higher blood pressure. So a normal blood pressure range for children accounts for age, height and gender.

Children’s Normal Blood Pressure Range:

•          3 – 5 years; upper limit systolic 104 – 116, upper limit diastolic 63 – 74
•          6 – 9 years; upper limit systolic 108 – 121, upper limit diastolic 71 – 81
•         10 – 12 years; upper limit systolic 114 – 127, upper limit diastolic 77 – 83

How is Blood Pressure measured?

Blood pressure is measured using a stethoscope and a sphygmomanometer, which contains a rubber cuff to wrap around the upper arm and a pump to inflate it with air. When inflated, pressure stops the blood flow for a moment. Then as air is release from the cuff, the blood flow starts up again. A stethoscope is placed over the arm to listen for the sound of blood pulsing through the arteries. The first sound of rushing blood refers to systolic pressure; once the sound fades, the second number indicates the diastolic pressure.

Convenient wrist model sphygmomanometers are available. The wrist one is probably the simplest. A firm cuff slips around the wrist; a small visual display unit is opened, and the button pressed. Within about one minute, the systolic and diastolic readings show up in large clear figures on the screen followed by the pulse rate.

Blood pressure is measured in mm Hg and recorded with the systolic number first, followed by the diastolic number.  Systolic blood pressure refers to the pressure inside the arteries when the heart is pumping; diastolic pressure is the pressure inside the arteries when the heart is resting between beats.

Blood pressure reading can be affected by factors like:

• Smoking
• Coffee or other caffeine drink
• A full bladder
• Recent physical activity

Blood pressure is also affected by emotional state and the time of the day. Since so many factors can affect blood pressure readings, blood pressure should be taken several times to get an accurate measurement.

Since high blood pressure can exist without any symptoms, it is important to know your numbers.  Getting your blood pressure checked is quick, painless, and one of the most important things you can do to better your health.

Reference

Goss, V.H., 2011. Normal Blood Pressure Range for Children. [Online]

Available: http://www.everydayhealth.com [2012, June 27]

Illiades, C. How is Blood Pressure Measured and What do the Numbers Mean? [Online].

 Available: http://www.livestrong.com [2012, June 27]

Wright, J. 2005. Family Medical Care, Vol. 3, Signs Publishing Company, Victoria, Australia, 7^th Ed., pp. 57.