Measuring Blood Pressure in Children

Mother taking care of her daughter in the hospital

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In This Article

There has been an upward trend in the number of children with hypertension (high blood pressure) in the United States. Unfortunately, many of these cases go undiagnosed and untreated, leading health officials to call for increased surveillance of blood pressure reading in kids.

According to data from the National Health and Nutrition Examination Survey (NHANES), up to 19 percent of American boys and 12 percent of American girls have hypertension. The prevalence increases with age and is especially high in Hispanic and African-American children. Boys are at greater risk than girls as are kids who are obese or have diabetes.

If left untreated, hypertension can persist into adulthood, increasing the risk of kidney disease, stroke, heart attack, and heart failure, often years before others in your age group.

Overview

Blood pressure readings taken at the doctor's office will become part of your child's medical history to preemptively identify any changes in blood pressure that may be problematic. Blood pressure reading involves two separate values:

  • Systolic blood pressure is the highest pressure level in arteries as the heart pumps blood to the rest of the body.
  • Diastolic blood pressure is the lowest pressure in the arteries when the heart relaxes between beats.

The blood pressure reading is delivered as your systolic blood pressure over your diastolic blood pressure. The pressure is measured in units called millimeters of mercury (mm Hg) which describes the level that mercury rises under pressure in a sphygmomanometer (blood pressure meter).

A blood pressure reading with a systolic value of 120 and diastolic value of 80 is written as 120/80 mm Hg.

Recommendations

Children should have routine blood pressure readings starting at age 3 as part of an annual physical exam. Blood pressure reading may be checked more frequently in children who:

  • Are significantly overweight or underweight
  • Have stayed in a neonatal intensive care unit (NICU) for an extended period of time
  • Have any known heart, lung, or circulatory problems
  • Have experienced medical complications before, during, or shortly after birth

Extra care should also be taken in children who have risks factors for hypertension, including:

It can be difficult to diagnose high blood pressure in kids because it changes with age and body size. It is only by routinely monitoring these changes that you can get an accurate picture of your child's health.

Procedure

If your doctor asks you to monitor your child's blood pressure, it is important that you do so correctly. It is important to remember that your child's blood pressure can fluctuate dramatically during the course of the day with activity, excitement, stress, and even a heavy meal. As a rule of thumb, only take a blood pressure reading when the child is calm.

To ensure an accurate reading, ask your child to sit quietly without kicking, crossing the legs, or holding their breath. The hands should be folded on the lap and not pressed to the sides.

There is no point in taking a blood pressure reading if your child is crying or screaming. If needed, you can calm the child with a treat or a video as long it doesn't excite them.

There are other variables you need to consider:

  • Cuff size: Since an incorrectly sized cuff can produce false readings, ask your pediatrician to a recommend a home unit best suited for your child's age and size. Newer home units do not require a stethoscope and are relatively fast and easy to use. Avoid drugstore machines that are designed solely for adults.
  • Timing: Recent physical activity can skew an otherwise good reading. To avoid this, wait until your child has been calm for at least five minutes before you begin.
  • Repetition: It is best to take three separate blood pressure readings at least two minutes apart. This will help compensate for any inconsistencies in your home blood pressure unit.
  • Consistency: Because blood pressure can vary throughout the day, try to take readings at more or less the same time. If you've taken a reading at 10:00 a.m. on a Saturday, try to keep to that schedule. Keep a record of all readings, including the date and time.

Even though your reading may not be as spot-on as an old fashioned cuff-and-stethoscope unit, the trending of results can still provide invaluable insights to your doctor.

If your child’s blood pressure is high during the doctor's visit, your pediatrician may ask you to come back in a week or two. If the readings are still high, the doctor may order additional tests to better pinpoint the cause.

Interpretations

Normal blood pressure ranges are continuously changing in children. They will be lowest in infants and continue to increase until around the age of 10. Boys tend to have higher blood pressure than girls, as do children with an increased body mass index (BMI).

The American Academy of Pediatrics (AAP) updated its clinical practice guidelines in 2017 to better define hypertension and prehypertension in children.

The guidelines differ from earlier versions in that they break down the definitions by age and sex, with older kids categorized by blood pressure readings and younger kids categorized by the risk percentile. (The risk percentile is your relative standing in relation to the rest of a population group.)

AAP Blood Pressure (BP) Definitions for Children and Adolescents
  Children under 13  Children 13 and over
Normal BP less than the 90th percentile for the age, sex, and height Systolic BP under 120 mm Hg and diastolic BP under 80 mmg Hg
Prehypertension BP between the 90th and 95th percentile for the age, sex, and height Systolic BP between 120 and 129 mg Hg and diastolic BP under 80 mm Hg
Hypertension BP equal to or greater than the 95th percentile for the age, sex, and height BP greater than 130/80 mm Hg
Stage 1 hypertension BP equal to or greater than the 95th percentile to under the 95th percent plus 12 mm Hg Systolic BP between 130 and 139 mm Hg and diastolic BP between 80 and 89 mm Hg
Stage 2 hypertension BP equal to or greater than the 95th percentile plus 12 mm Hg BP greater than 140/900 mm Hg

A Word From Verywell

Many children and teens with hypertension have unhealthy habits, including a poor diet, excess weight, and too little physical exercise. Stress is also a major contributing factor caused by everything from school, family, and social life.

If your child is diagnosed with high blood pressure, you need to intervene as a parent to correct the problems for not only your child but the rest of the family. It does not help to isolate the child with rules and practices if others are engaging in the same unhealthy practices.

Regular exercise, an improved diet, weight loss, reduced screen time, and stress-reduction techniques are some of the things you can all explore for the betterment of your entire family.

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Article Sources

  1. Jackson SL, Zhang Z, Wiltz JL et al. Hypertension Among Youths—United States, 2001-2016. MMWR Morb Mortal Wkly Rep. 2018 Jul 13;67(27):758-62. doi:10.15585/mmwr.mm6727a2.

  2. Flynn JT, Kaelber DC, Baker-Smith CM, et al. Clinical Practice Guideline for Screening and Management of High Blood Pressure in Children and Adolescents. Pediatrics. 2017; 140(3):e20171904. doi:10.1542/peds.2017-1904.

  3. Flynn JT, Falkner BE. New Clinical Practice Guideline for the Management of High Blood Pressure in Children and Adolescents. Hypertension. 2017;70:683-6. doi:10.1161/HYPERTENSIONAHA.117.10050.

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