Essential hypertension is quite rare in childhood or adolescence even if the prevalence is increasing. A secondary cause behind the raised blood pressure should therefore be searched, e.g. renal disease, aortic coarcation, endocrine causes, raised intracranial pressure etc. Blood pressure medication should not be commenced before aetiological examinations have been conducted in specialist care.
Blood pressure is elevated if it repeatedly exceeds the threshold values indicated in table T1. In such as case, the aetiological causes of the elevated blood pressure should be investigated. Find out patient history concerning risk factors (e.g. overweight, physical exercise, salt consumption, use of liquorice or stimulants), family history, pharmaceuticals (e.g. ADHD drugs) and possible other illnesses.
A child has hypertension if blood pressure repeatedly exceeds the threshold values indicated in table T1 by 12 mmHg. In children over 13 years old, the respective blood pressure level is ≥ 130/80 mmHg. If the threshold values are exceeded repeatedly, the child should, at the latest, be referred for investigations by a specialist.
Blood pressure reference values (90% percentile, i.e. highest acceptable values).
Age (yrs)
Boys
Girls
1
98/52
98/54
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
Clinical examination
The cuff width should be two thirds of the length of the upper arm when the BP reading is taken from the right arm. The same cuff can be used when the reading is taken from the leg. If the reading is taken from the thigh the cuff width should be two thirds of the length of the thigh. The chosen cuff should preferably be too wide than too narrow.
The diagnosis of systemic hypertension should be based on repeated blood pressure measurements within a few days. BPs from the right arm should be measured at least three times. Diastolic BP is defined as the disappearance of Korotkoff sounds (K5). If the sounds do not disappear, the point where they soften (K4) is recorded.
Oscillometric devices for BP measurements may yield BP values slightly differing from those obtained with a sphygmomanometer (which is the standard method). Therefore, at least in borderline cases, sphygmomanometers should be used.
BP is always measured also from the thigh (sphygmomanometer) or leg to rule out or to confirm aortic coarctation. When an oscillometric device is used, lower limb BP is measured from the leg above the malleolar level. Normally the systolic pressure measured from the leg is at least as high as the systolic pressure measured from the right upper arm.
Auscultation of the heart
The femoral artery pulses are felt. If they cannot be felt or if they are weaker or delayed as compared to the brachial artery, aortic coarctation must be ruled out.
Palpation of the abdomen (renal cysts, tumours)
Check for signs of endocrinological diseases (habitus typical of Cushing's syndrome, pigmentation) and signs of Turner's syndrome (short stature).
Aetiology and differential diagnosis
Neonates and infants
Aortic coarctation
Congenital malformations of the kidneys
Renal artery stenosis (or thrombosis)
1-10-year-olds
Renal parenchymal disease
Aortic coarctation
Renal artery stenosis
11-18-year-olds
Renal parenchymal disease
Aortic coarctation
Essential hypertension (rare; secondary hypertension must always be excluded!)
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). [PubMed]