An 8-year-old female comes to clinic for a health maintenance visit. The visit is unremarkable except that a blood pressure of 109/67 mm Hg which was noted.
The past medical history is negative.
Her family history is negative for cardiovascular, renal or endocrine disease.
The pertinent physical exam shows her to have growth that is 25% for height and weight. The auscultated repeat blood pressure is 111/64. Four point blood pressures show no difference between arms and are not significantly different in the upper or lower extremities.
The chart review shows normal blood pressures in the past, and previous laboratory evaluation shows a normal BUN, creatinine and urinalysis.
The diagnosis of possible borderline hypertension is made. The child was sent home to have bi-weekly blood pressure measurements by the school nurse and follow-up in 3-4 weeks.
Hypertension is a serious disease causing morbidity and mortality. Hypertension is defined as a blood pressure persistently greater than the 95th percentile for age, height and gender in children. In adults, hypertension is defined as blood pressures >140/90 mm Hg.
Children with blood pressures within the upper percentiles of the normal range (>90th percentile or >120/80 for adolescents) are also at risk of becoming hypertensive in the future. The is called prehypertensive. Consequently as part of overall health maintenance, blood pressures should be recorded at least yearly after age 3 and at younger ages if indicated.
Essential hypertension is the most common cause of hypertension in children. Obesity is the primary cause of essential hypertension in the U.S. currently. Common secondary causes of hypertension in children include the following:
- Cardiac (10%)
- Coarctation of the aorta
- Renal (80%)
- Congenital renal anomalies
- Renal vascular problems – renal artery stenosis, renal artery or vein thrombosis, neurofibromatosis
- Renal parenchymal disease – renal failure, glomerulonephritis, reflux nephropathy, structural abnormalities
- Endocrine (2%)
- Congenital adrenal hyperplasia
- Conn’s syndrome
- Cushing’s disease
- Hypo- or hyperthyroidism
- Central nervous system tumors
- Wilm’s tumor
- Other malignancies
- Acute intermittent porphyria
- Bronchopulmonary dysplasia
- Genetic syndromes such as Bardet-Biedl, von Hippel-Landau, Williams, Turners, Neurofibromatosis
- Guillian-Barre syndrome
- Over-the-counter cough and cold medications
- Recent vigorous exercise
- Recent smoking, alcohol or other medication use (including illicit drugs)
When evaluating hypertension, one must first determine that there is truly hypertension. In the office setting, the blood pressure can easily be rechecked ensuring the correct size cuff is used (i.e. covers 2/3 of the distance between the elbow and shoulder or knee to hip) and the proper number recorded. Repeated measurements (at least 3) are needed and often can be done at school or other location. This is more convenient for families often and children are less likely to have white-coat syndrome where their blood pressure is only elevated in the doctor’s office but not in other settings.
If the blood pressure is still high, then a work-up to find a potentially correctable cause of hypertension should be done. This should include: blood pressure measurement in all four extremities, BUN, creatinine, urinalysis, and CBC. Cardiac echocardiogram looking for ventricular hypertrophy can also be helpful. Additionally, some people also obtain plasma renin level, cholesterol and triglycerides and a renal ultrasound with Doppler.
Other specific testing should be guided by the history, physical examination and laboratory evaluation results.
Treatment for hypertension includes diet, exercise and possibly medication.
Often, a rough estimate of blood pressure above which a health care provider should be concerned is all that is needed by the provider. One rough estimate of age-adjusted blood pressures uses the following formula:
90/50 + (3/1.5)(Age in Years)
Where systolic blood pressure begins with 90 and (3 x age in years) is added And diastolic blood pressure begins with 50 and (1.5 x age in years) is added
For this patient who is 8 years old:
Systolic blood pressure = 90 + (3x8) = 90 + 24 = 114 Diastolic blood pressure = 50 + (1.5x8) = 50 + 12 = 62
Or the rough estimate of a age-adjusted borderline blood pressure is 114/62.
It should be emphasized that this is AN ESTIMATE ONLY.
If the patient’s blood pressure is close to the estimate or if the healthcare provider is unsure or concerned, then the standards based on gender, age and height standards must be checked. These standards can be found in the To Learn More section below.
For this patient, the standard would be 110/71.
Questions for Further Discussion
1. What medications are commonly used to treat hypertension?
To Learn More
To view pediatric review articles on this topic from the past year check PubMed.
Information prescriptions for patients can be found at Pediatric Common Questions, Quick Answers for this topic: High Blood Pressure.
Update on the 1987 Task Force Report on High Blood Pressure in Children and Adolescents: a working group report from the National High Blood Pressure Education Program. National High Blood Pressure Education Program Working Group on Hypertension Control in Children and Adolescents
Gunn VL, Nechyba C. The Harriet Lane Handbook. 16th. Edit. Mosby Publications: St. Louis. 2002:126-129.
Woodhead JC. Pediatric Clerkship Guide. Mosby., St. Louis MO, 2003:277-284.
Spitzer, A. Hypertension. eMedicine.
Available from the Internet at http://www.emedicine.com/ped/topic1097.htm (rev. 6/29/04, cited 12/13/04).
Donna M. D’Alessandro, MD
Associate Professor of Pediatrics, Children’s Hospital of Iowa
January 5, 2005