Normal Blood Pressure in children and Definition of HypertensionNormal blood pressure in children varies according to age, gender and height of a child. There are normal values of systolic and diastolic BP which are recorded in large number of school children and like growth charts, percentile charts of BP are available for different ages as per 3rd Task for blood pressure in children which is compiling data from USA and Europe. If 3 separate BP recordings of a child are above 95th centile for age, gender and height it is designated as hypertension or high BP.
Causes of hypertension Causes of Hypertension in children in 80 - 85% of cases are due to kidney diseases like glomerulonephritis, urinary tract infections or pyelonephritis, collagen vascular diseases such as lupus erythematosus, hemolytic uremic syndrome, renal tumors like Wilm's tumor, congenital anomalies such as polycystic kidney disease or hereditary causes such as Alport's syndrome. Renal artery stenosis or aortoarteritis are renovascular causes of hypertension. Less than 5% are due to endocrinal disorders such as Cushing's or adrenal hyperplasia and adrenal tumors i.e. pheochromocytoma or neuroblastoma.
Co-arctation of aorta and patent ductus arteriosus are in less than 3% hypertensives and rare cases of meningitis, encephalitis, brain tumors are CNS causes. Less than 1 - 2% hypertensive children are due to essential or primary hypertension in preadolescent age group.