Hypertension is sustained elevation of resting systolic blood pressure, diastolic blood pressure, or both; the pressures considered abnormal in children vary based on age up to age 13. Hypertension with no known cause (primary) is most common as with adults. Hypertension with an identified cause (secondary hypertension) is relatively uncommon in children. Usually, children have no symptoms or complications of hypertension during childhood, although these may develop later. Diagnosis is by sphygmomanometry. Tests may be done to look for causes of secondary hypertension. Treatment involves lifestyle changes, drugs, and management of treatable causes.
It has become clear over the past few decades that adult hypertension is affected by both intrauterine and neonatal conditions and often begins in childhood. Also, sequelae of hypertension in adulthood occur earlier in patients who were hypertensive as children. Thus, it is important to identify and treat hypertension in children.
In the US, the prevalence of hypertension in children ranges between 2.2% and 3.9% with high normal readings between 3.4% and 4%. Worldwide, prevalence is less clear because of regional differences in definitions, reference data, and methodology but is estimated at about 4%. In addition, the prevalence appears to be increasing, likely due to the increased incidence of overweight and obesity in children; obesity is now twice as common among adolescents as it was 30 years ago (see Obesity in Adolescents). Obese adolescents are more likely than their peers to have hypertension.
Definition of hypertension in children
Because there are no outcomes data for hypertension in children, hypertension in children < 13 years of age is classified normatively, ie, in comparison to blood pressure measurements in a large group of children. Normative blood pressure values in children < 13 years of age vary by age, sex, and height (see blood pressure percentile level tables for boys and girls).
Blood pressure in children ≥ 13 of age is classified based on actual blood pressure values (see table Classification of Blood Pressure (BP) in Children).
Classification of Blood Pressure (BP) in Children
Classification | Age 1 to < 13 Years, BP | Age ≥ 13 Years, BP |
|---|---|---|
Normal | < 90th percentile* | < 120/< 80 |
Elevated | ≥ 90th percentile (or ≥ 120/80, whichever is lower) to < 95th percentile | 120–129/< 80 |
Stage 1 hypertension | ≥ 95th percentile to < 95th percentile + 12 mm Hg OR 130/80 to 139/89, whichever is lower | 130/80 to 139/89 |
Stage 2 hypertension | ≥ 95th percentile + 12 mm Hg OR ≥ 140/90, whichever is lower | ≥ 140/90 |
* Percentiles refer to systolic BP. | ||
Adapted from Flynn JT, Kaelber DC, Baker-Smith CM, et al: Clinical practice guideline for screening and management of high blood pressure in children and adolescents, table 3. Pediatrics 140(3):e20171904, 2017. doi: 10.1542/peds.2017-1904 | ||
Etiology of Hypertension in Children
Hypertension may be
Primary (no known cause, a diagnosis of exclusion)
Secondary (caused by another disorder, eg, kidney disease)
After age 6, primary hypertension is by far the dominant etiology, and this is even more true for adolescents. Before age 6, secondary hypertension is more common, and this is more true for children under the age of 3.
Primary hypertension
By definition, the cause of primary hypertension is not known, which is why it is a diagnosis of exclusion. However, it is known to be more common among children who
Are overweight or obese (most important risk factor for primary hypertension)
Have a family history of hypertension
Are male
Are Mexican-American or non-Hispanic black (in the US)
Have a sedentary lifestyle
Have unhealthy dietary habits (eg, high salt and calorie intake)
Had various intrauterine factors (eg, resulting in low birth weight, prematurity, or small for gestational age)
Have social risk factors (eg, child abuse, family and/or interpersonal violence, food and/or housing insecurity—the number, duration, and severity of these factors have a cumulative effect)
Secondary hypertension
Secondary hypertension has an identifiable cause; the hypertension may be reversible if the cause is resolved.
The most common causes of secondary hypertension in children are
Renal parenchymal disease (eg, glomerulonephritis, pyelonephritis, reflux nephropathy) or renal structural abnormalities (eg, obstructive uropathy, polycystic kidney disease, dysplastic kidneys)
Renovascular disease (eg, renal artery stenosis, renal vein thrombosis)
Cardiovascular disease (eg, coarctation of the aorta, arteriovenous fistula)
Endocrine disease (eg, hyperthyroidism, mineralocorticoid excess, corticosteroid excess, catecholamine excess)
Other causes of secondary hypertension include
Sleep-disordered breathing
Neurologic causes (eg, increased intracranial pressure)
Psychologic stress or pain
Miscellaneous causes (eg, neuroblastoma, tuberous sclerosis complex, Wilms tumor)
Orthopedic-related hypertension is related to traction or casting of a lower extremity, usually after a femur fracture. This type of hypertension is thought to be caused by pressure on the femoral nerve.
Pathophysiology of Hypertension in Children
As in adults, blood pressure is determined by the balance between cardiac output (affected by myocardial contractility, heart rate, and vascular volume) and vascular resistance (affected by vascular structure and function). The renin-angiotensin-aldosterone system, sympathetic nervous system, sodium transport, and other factors play a role (for further information, see pathophysiology of hypertension). Unlike in older adults, in children and younger adults cardiac output and volume status are more likely to be the prominent driving forces of hypertension, but with aging, vascular structural changes with increased vessel wall thickness and stiffness (which increase vascular resistance) play a more important role.
Complications of pediatric hypertension
Complications of pediatric hypertension can be
Acute
Chronic
Acute complications of hypertension in children are relatively uncommon and are usually related to hypertensive emergencies, in which end-organ dysfunction or damage is present. Affected organs include the central nervous system (causing encephalopathy, including seizures, lethargy, and/or coma), heart (causing heart failure), eyes (causing papilledema, retinal hemorrhages), and kidneys (causing renal insufficiency).
Chronic complications of hypertension in children are rare and when present typically do not occur until late adolescence or early adulthood. The complications of chronic hypertension in adults, including coronary artery disease, heart failure, ischemic stroke, and hypertensive end-stage renal disease, rarely, if ever, occur in children. However, there are findings in children that seem to predict later development of these complications. The best-studied and most accurate predictor is the development of left ventricular (LV) hypertrophy (diagnosed by echocardiography). When normalized for height, age, and sex, an LV mass > 51 g/m2 is considered excessive. This finding is a clear reason to begin antihypertensive therapy during childhood.
Symptoms and Signs of Hypertension in Children
Hypertension in children, with the rare exception of hypertensive emergencies, is usually asymptomatic.
The physical examination may be normal (other than the elevated blood pressure), but signs of hypertension and/or its causes are sometimes present and should be specifically sought, including
Eyes: Proptosis (hyperthyroidism), hypertensive retinopathy (arteriolar spasm, hemorrhages, exudates, and rarely papilledema)
Head and face: Moon facies (corticosteroid excess, such as Cushing syndrome), tonsillar hypertrophy (sleep apnea)
Neck: Thyroid enlargement and/or tenderness (hyperthyroidism)
Heart: Murmur (coarctation of the aorta), friction rub (collagen vascular disease), apical heave (left ventricular hypertrophy)
Abdomen: Mass (tumor, cystic kidney disease, hydronephrosis), bruit (renovascular disease)
Extremities: Edema (kidney disease), joint swelling (collagen vascular disease), lower extremity traction or cast (orthopedic-related hypertension)
Genitalia: Ambiguous/virilization (adrenal hyperplasia), advanced puberty (intracranial tumor)
Skin: Pallor/flushing (catecholamine excess), acne/hirsutism/striae (Cushing syndrome, corticosteroid therapy), café-au-lait spots/neurofibromas (neurofibromatosis), ash-leaf spots/adenoma sebaceum (tuberous sclerosis complex), rash (systemic lupus erythematosus, immunoglobulin A–associated vasculitis)
Neurologic: Muscle weakness (hyperaldosteronism, Liddle syndrome)
General: Obesity (primary/essential hypertension), growth retardation (chronic kidney disease)
Vital signs: Tachycardia (hyperthyroidism, catecholamine excess), blood pressure difference between the extremities (coarctation of the aorta, mid-aortic syndromes [1])
Symptoms and signs reference
1. O'Neill JA, Berkowitz H, Fellows KJ, Harmon CM: Midaortic syndrome and hypertension in childhood. J Pediatr Surg 30(2):164–171; discussion 171-2, 1995. doi: 10.1016/0022-3468(95)90555-3
Diagnosis of Hypertension in Children
Sphygmomanometry (auscultation)
Oscillometric devices
Sometimes testing for etiology
Because blood pressure (BP) values vary based on age, sex, and height, hypertension is defined based on normative values (see BP percentile level tables for boys and girls). Hypertension should typically not be diagnosed until high BP values (as defined in table Classification of Blood Pressure in Children) have been identified on three separate visits in order to exclude transient causes of BP elevation, such as recent consumption of caffeinated beverages or white coat hypertension (ie, BP elevation due to the anxiety of a doctor visit).
BP measurement must be done using proper technique. Children should be sitting quietly in a chair with their back supported and feet on the floor for 3 to 5 minutes before measurement. It is critical to use a cuff of the correct size; a range of cuff sizes, including a thigh cuff, should be available. The cuff width should be at least 40% of the circumference of the middle of the upper arm and the length of the inflatable bladder should be 80 to 100% of that circumference. A cuff that is too narrow results in erroneously high BP values, whereas a cuff that is too wide results in incorrectly low BP values. In general, at least two measurements should be taken at each visit, particularly if the initial measurement is high.
Blood pressure screening
Today, most BP screening is done using oscillometric devices because they are easy to use, reduce observer bias, and are better tolerated by younger children and infants. Measurements taken with an oscillometric device are usually higher than measurements obtained by auscultation, so any measurement ≥ the 90th percentile needs to be confirmed by auscultation.
According to the American Academy of Pediatrics' (AAP) 2017 guidelines for high blood pressure in children and adolescents, routine BP monitoring should be done annually beginning at age 3 years. If BP is below the 90th percentile or below the BP value requiring additional evaluation per AAP guidelines, measurement is continued annually. Children with risk factors for hypertension, such as kidney disease, cardiac disease, or a significant neonatal history, should be evaluated earlier and more frequently—at each visit.
To simplify screening, the AAP guidelines provide BP values for each age that, although not diagnostic of hypertension, indicate need for further evaluation (see table Screening Blood Pressure Values in Children That Need Additional Evaluation). These values represent the 90th percentile BP for the smallest height cohort at each age 1 through 12 years, so screening practitioners do not need to determine precise BP percentiles in every child. Further evaluation typically begins with repeat measurements and calculation of actual BP percentile (see table Classification of Blood Pressure (BP) in Children), and then follow up with a physician (ie, if screening done by other personnel).
Screening Blood Pressure Values in Children That Need Additional Evaluation*
Age (years) | Boys | Girls | ||
|---|---|---|---|---|
Systolic | Diastolic | Systolic | Diastolic | |
1 | 98 | 52 | 98 | 57 |
2 | 100 | 55 | 101 | 58 |
3 | 101 | 58 | 102 | 60 |
4 | 102 | 60 | 103 | 62 |
5 | 103 | 63 | 104 | 64 |
6 | 105 | 66 | 105 | 67 |
7 | 106 | 68 | 106 | 68 |
8 | 107 | 69 | 107 | 69 |
9 | 107 | 70 | 108 | 71 |
10 | 108 | 72 | 109 | 72 |
11 | 110 | 74 | 111 | 74 |
12 | 113 | 75 | 114 | 75 |
≥ 13 | 120 | 80 | 120 | 80 |
* Note, these values are not intended to diagnose or classify hypertension and should be used only for screening to identify children whose blood pressure requires a more thorough evaluation. | ||||
Adapted from Flynn JT, Kaelber DC, Baker-Smith CM, et al: Clinical practice guideline for screening and management of high blood pressure in children and adolescents, table 6. Pediatrics 140(3):e20171904, 2017. doi: 10.1542/peds.2017-1904 | ||||
Children with BP between the 90th and 95th percentiles should be rechecked by auscultation within 6 months because 50 to 70% return to the normal range. If BP remains elevated after 6 months, lifestyle changes (eg, diet, activity, weight loss if needed) should be recommended and upper and lower extremity BP measurements should be taken. If BP remains elevated over the next 6 months, 24-hour ambulatory BP monitoring could be done, if possible, or the patient could be referred to a specialist. However, if during this time BP returns to below the 90th percentile, the annual monitoring schedule can be resumed.
If measurements are consistently ≥ 95th percentile but < 95th percentile + 12 mm Hg, children should be considered to have stage 1 hypertension (see also table Classification of Blood Pressure in Children). Measurements that are ≥ 95th percentile + 12 mm Hg or ≥ 140/90, whichever is lower, represent stage 2 hypertension.
Children with stage 1 hypertension should be rechecked within 1 to 2 weeks. If BP remains at stage 1, upper and lower extremity BP measurements should be taken, a urinalysis done, and lifestyle changes recommended. BP should be rechecked in 2 to 3 months and if still at stage 1, children should be referred to a specialist for evaluation, including determination of cause. Children with stage 2 hypertension or stage 1 hypertension with symptoms should be referred immediately to an emergency department or a pediatric specialist for possible hospitalization.
Evaluation of cause
Specific testing should be done for any disorders suspected based on the history and physical examination (eg, thyroid function tests if hyperthyroidism is suspected).
Children ≥ 6 years of age and adolescents who have asymptomatic stage 1 hypertension and a positive family history of hypertension, who are overweight or obese, and who do not have a suggestive history or physical examination findings do not require an extensive evaluation for secondary hypertension. Initial testing for these children can be simplified to include measurement of BUN, creatinine, electrolytes, and calcium and an in-office screening urine dipstick test. If these results are normal and there is no difference between upper and lower extremity BP measurements, diet and lifestyle changes (eg, activity, weight loss if needed) should be started and children should be reevaluated in 6 months. If BP remains elevated and weight is unchanged or has increased after 6 months, further evaluation should be done to look for other causative factors for hypertension. Children who have asymptomatic stage 1 hypertension for 3 readings but without a family history and who are not overweight should have this evaluation done within a month or two. Children and adolescents who have stage 2 hypertension or stage 1 hypertension with symptoms should have immediate evaluation.
Further evaluation includes the following tests:
Fasting complete metabolic panel (including glucose, liver enzymes, and lipid panel), and glycosylated hemoglobin (HbA1c—for prediabetes)
Echocardiography (for left ventricular hypertrophy)
Renal ultrasonography
If test results are normal, diet and lifestyle changes are continued for another 6 months, and consultation with a nutritionist can be suggested. However, if there is evidence of a comorbid condition, BP remains elevated, and weight has not decreased, drug therapy should be considered.
Children < 6 years of age who are not overweight and who lack a significant family history of hypertension, all children ≤ 3 years of age, and those with stage 1 hypertension with symptoms or stage 2 hypertension should have a more complete initial evaluation, keeping in mind that the higher the BP and the younger the child, the more likely a cause of secondary hypertension will be found. Finally, children between the ages of 3 years and 6 years who are overweight with a family history of hypertension should have this evaluation done before allowing them to have only lifestyle changes. These children should have the following tests:
Comprehensive metabolic panel
Complete blood count
Urinalysis
Plasma renin activity and aldosterone levels
Thyroid function tests
Evaluation of catecholamine activity (eg, by measuring plasma free metanephrines)
Renal ultrasonography with Doppler flow
Echocardiography
The other option for these children is an early referral to a pediatric nephrologist because most of the common causes of secondary hypertension in children are kidney related. A pediatric nephrologist would do this same evaluation along with other renal imaging such as a technetium-99m-labeled dimercaptosuccinic acid (DMSA) renal scan (to look for renal scarring) and/or digital subtraction angiography (to evaluate for renal vascular disease).
Treatment of Hypertension in Children
Weight reduction
Dietary modification (salt and calorie reduction)
Exercise
Sometimes drug treatment
Treatment of hypertension in children includes a combination of weight reduction, diet, exercise, and sometimes drug treatment depending on the stage of hypertension. Children with stage 2 hypertension, or stage 1 hypertension with symptoms, evidence of end-organ damage, diabetes, or renal disease should be referred to a specialist to begin a more rapid and correct therapy.
Treatment goals are typically a BP of < 90th percentile or, in older children, < 130/80, whichever is lower; some centers have a treatment goal of < 120/80. For children with renal disease, the goal is a mean 24-hour BP below the 50th percentile.
Lifestyle changes that can help lower BP, including dietary modification and exercise, are started in all children with elevated BP. The keys to weight reduction in childhood are healthy eating habits and increased physical activity. A diet higher in fruits, vegetables, legumes, and low-fat dairy products and lower in salt, such as the DASH (Dietary Approaches to Stop Hypertension) diet, has been associated with lower BP. Dietary changes also should include a calorie limit based on activity level, age, and sex. Salt intake should be < 2300 mg/day in children over 13 years of age and < 2 to 3 mEq/kg/day in younger children. Children ages 6 to 17 years should be doing 30 to 60 minutes of moderate to vigorous physical activity each day or at least 3 to 5 days a week. Younger children should be physically active throughout the day.
Drug treatment is begun immediately in certain children and later in others if a trial of lifestyle changes fails to control BP.
Drug treatment of hypertension in children
Immediate drug treatment is typically started (along with lifestyle changes) for children with
Symptomatic hypertension at any stage or level
Stage 1 hypertension with any evidence of end-organ dysfunction or damage
Stage 2 hypertension even with an obvious, modifiable risk factor (eg, obesity), which should be addressed while BP is being controlled
Any stage of hypertension if they have chronic kidney disease, diabetes, or cardiac disease
In children with high normal or borderline hypertension or stage 1 hypertension without symptoms or end-organ dysfunction, lifestyle changes are initiated, and if these do not sufficiently lower BP within about 6 months, drug treatment will be necessary.
Generally, drug treatment should begin with a single drug at the low end of its dosing range and increased every 1 to 4 weeks until BP is controlled, the upper end of the dosing range is approached, or adverse effects develop that affect the use of the drug. At that point, if the BP goal has not been attained, a second drug can be added and titrated as with the initial drug. Classes of oral drugs used to treat hypertension include
Adrenergic modifiers (beta- and alpha-antagonist, alpha-2-agonist, beta-blocker)
For a more detailed discussion of each class and its specific drugs, see Drugs for Hypertension in Children.
Oral therapy for persistent hypertension in children should generally begin with an angiotensin-converting enzyme (ACE) inhibitor or a calcium channel blocker (CCB). (ARBs are equally effective and do not cause a cough, but there are more data in children on the use of ACE inhibitors.) Both classes of drugs can be given as a single daily dose and seem to be equally effective. ACE inhibitors should be used in patients with chronic kidney disease or diabetes because these drugs may also protect the kidneys. CCBs should be used in menstruating girls if there is risk of pregnancy because ACE inhibitors and ARBs have significant effects on a fetus. CCBs also have no significant effect on blood chemistries. Thiazide diuretics have been used as initial treatment, but salt intake in adolescents is usually so high that they are rarely effective.
Prevention
Weight reduction
Exercise
Reducing salt intake
Reduction of cardiovascular risk factors
Childhood obesity has become a major problem. Children are spending an inordinate amount of time in front of a screen. According to the Centers for Disease Control and Prevention (CDC), children 8 to 10 years old spend an average of 6 hours per day, children 11 to 14 spend an average of 9 hours per day, and children 15 to 18 spend an average of 7½ hours per day. These totals include only the time spent in front of a screen for entertainment. They do not include the time spent using a computer at school for educational purposes or at home for homework. This amount of screen time comes at the expense of exercise and thus contributes to overweight and obesity.
Children ages 6 to 17 should be doing 30 to 60 minutes of moderate to vigorous physical activity at least 3 to 5 days per week. Younger children should be physically active throughout the day.
According to the CDC, children ages 6 to 18 in the US consume about 3300 mg of sodium per day (1), and this is before salt is added at the table. The U.S. Department of Agriculture and U.S. Department of Health and Human Services 2020–2025 Dietary Guidelines for Americans recommend that children consume less than 2300 mg per day (even less for children < 13 years).
It is important to screen for smoking in children and, where necessary, help implement a smoking cessation program
Prevention reference
1. Yang Q, Zhang Z, Kukline EV, et al: Sodium intake and blood pressure among US children and adolescents. Pediatrics 130(4): 611–619, 2012. doi: 10.1542/peds.2011-3870
Key Points
Most hypertension in children is primary.
Confirm diagnosis of hypertension with readings on three different visits.
Rule out secondary causes of hypertension by physical examination and laboratory tests.
Initiate treatment with lifestyle changes, primarily diet and exercise.
If lifestyle changes are insufficient, add drug treatment, beginning with either a calcium channel blocker or an angiotensin-converting enzyme inhibitor.
Titrate drug dosing and drugs until optimal blood pressure is reached.
More Information
The following are English-language resources that may be useful. Please note that THE MANUAL is not responsible for the content of these resources.
American Academy of Pediatrics: Clinical Practice Guideline for Screening and Management of High Blood Pressure in Children and Adolescents (2017)
U.S. Department of Agriculture and U.S. Department of Health and Human Services: 2020–2025 Dietary Guidelines for Americans
