High blood pressure, or hypertension, can occur in children as it does in adults. However, common causes for the disorder differ between the two age groups. While primary hypertension--high blood pressure not due to another disorder--predominates in adults, most hypertension in prepubertal children occurs due an underlying medical condition that precipitates high blood pressure. Kidney diseases and blood vessel malformations most commonly cause childhood hypertension.
Kidney Disease
In a review article on causes of high blood pressure in children and adolescents published in "American Family Physician," Drs. Gregory Luma and Roseann Spiotta report that kidney disease accounts for approximately 60 to 70 percent of hypertension in the pediatric population, especially among children who have not yet reached puberty. Abnormal water and salt retention due to kidney disease causes an increase in total fluid volume in the body, leading to high blood pressure. According to "The Merck Manual for Healthcare Professionals," kidney diseases that may cause high blood pressure in children include membranous nephropathy, focal segmental glomerulosclerosis, minimal change disease, membranoproliferative glomerulonephritis, diffuse mesangial sclerosis, Alport's syndrome and Finnish-type nephrotic syndrome.
Renal Artery Stenosis
The renal arteries deliver blood to the kidneys. Narrowing of these arteries, termed renal artery stenosis, can significantly decrease kidney blood flow. The kidneys respond to decreased blood flow by markedly increasing salt and water retention, leading to high blood pressure, explains the National Institute of Diabetes and Digestive and Kidney Diseases. While renal artery stenosis most commonly develops in older adults due to atherosclerosis, children may be born with narrow renal arteries. Establishing normal blood flow through the renal arteries, using stents to hold the arteries open or surgical repair of the blood vessels, usually reverses high blood pressure associated with this condition.
Coarctation of the Aorta
Coarctation of the aorta is a congenital blood vessel defect. The aorta transports oxygenated blood from the heart to other arteries that deliver the blood to the rest of the body. Coarctation of the aorta is an abnormal narrowing of the aorta that usually occurs just below the area where the upper body arteries branch off. The narrowing, or coarctation, causes increased blood flow to the upper body and decreased blood delivery to the lower body, including the kidneys. As with renal artery stenosis, the kidneys respond to the decreased blood flow by increasing salt and water retention, leading to high blood pressure. Hypertension in the upper extremities and weak arterial pulses in the lower extremities are the hallmark signs of coarctation of the aorta. Relieving aortic narrowing with a stent or surgical repair typically resolves hypertension associated with this condition.
References
- "American Family Physician"; Hypertension in Children and Adolescents; Gregory B. Luma, M.D., Roseann T. Spiotta, M.D.; May 2006
- Mayo Clinic: High Blood Pressure in Children, Risk Factors
- National Institute of Diabetes and Digestive and Kidney Diseases: Overview of Kidney Diseases in Children
- National Institute of Diabetes and Digestive and Kidney Diseases: Childhood Nephrotic Syndrome
- Merck Manual for Healthcare Professionals: Nephrotic Syndrome
