not always provided in such studies, with prevalence for secondary hypertension varying and reported between 0 and 0.2% in various surveys.194 These surveys varied according to their design, and the selection and referral to hospital for investigations In the Muscatine study,121 0.1% had secondary hypertension Results obtained from other surveys produced figures of 0.07%,201 0.11%,202 and 0.17%.203 Causes Younger children are more likely to have secondary hypertension as opposed to adolescents;204,205 with those with severe hypertension usually displaying an underlying cause as opposed to those with lower levels of hypertension.205 In a single-center report including 636 children with sustained and significant hypertension from Europe, secondary hypertension was found in 55% of patients, rising to 98% of all children younger than 16 years.206 Many conditions can be associated with hypertension (Box 60.1), and even this lengthy list is not exhaustive.207 The list of causes of drug-induced hypertension continues to increase.36,221 Box 60.1 Causes of Hypertension During Childhood Parenchymal Renal Disease Glomerulonephritis ■ Postinfection ■ IgA nephropathy, HSP nephritis ■ Lupus nephritis ■ ANCA associated nephritis ■ Anti-GBM nephritis Focal and segmental glomerulosclerosis Pyelonephritis related renal scarring Acute kidney injury with salt and water overload ■ Polycystic kidney disease ■ Chronic kidney disease ■ Obstructive uropathy Solid Organ Transplantation Renovascular ■ Renal artery stenosis ■ Idiopathic ■ Fibromuscular dysplasia ■ Neurofibromatosis type 1 ■ Williams syndrome ■ Mid-aortic syndrome ■ Thrombosis of renal artery or vein ■ Acute or post hemolytic uremic syndrome ■ Fistulae ■ External compression Endocrine ■ Cortisol/glucocorticoid excess ■ Aldosterone/mineralocorticoid excess ■ Catecholamine excess ■ Congenital adrenal hyperplasia ■ Thyroid disease Monogenic Causes Apparent mineralocorticoid excess Liddle syndrome Glucocorticoid remediable aldosteronism Congenital adrenal hyperplasia Gordon syndrome Cardiovascular Coarctation of aorta ■ Thoracic or abdominal ■ Takayasu arteritis Central Nervous System Pain Convulsions Increased intracranial pressure Guillain-Barré syndrome Dysautonomia Malignancy Wilms tumor (nephroblastoma) Neuroblastoma Pheochromocytoma Drugs Amphetamine, cocaine or other sympathomimetics Antidepressants and antipsychotics Acute vitamin D intoxication, hyperkalemia Oral contraceptive pills Calcineurin inhibitors (cyclosporine/tacrolimus) Decongestants containing phenylephrine and pseudoephedrine Erythropoiesis stimulating agents Glucocorticoids NSAIDs Recent discontinuation of antihypertensive drug(s) Other Obstructive sleep apnea Bronchopulmonary dysplasia Primary hypertension