We reviewed the records of 132 children with persistent hypertension w
ho were evaluated by our pediatric nephrology services between 1987 an
d 1991. Eighty-nine (67%) of these children were found to have renal o
r renovascular disease, 30 (23%) had primary hypertension and 13 (10%)
had a non-renal cause for their hypertension. Glomerulonephritis (n =
37) and reflux nephropathy (n = 26) were the most frequent renal diso
rders identified. Renal artery thrombosis was the most common cause of
hypertension in the neonatal period (in 6 of 12 neonates, 50%) wherea
s cystic kidney disease was the most common cause of hypertension in t
he lst year of life (in 9 of 30 infants, 30%). The prevalence of prima
ry hypertension increased with age; this diagnosis was made in 16 of 4
6 (35%) hypertensive patients between 12 and 18 years of age and, more
surprisingly, in 8 of 27 (30%) children between 7 and 11 years of age
. These data confirm that secondary hypertension is the most common ca
use of hypertension in children but suggest that primary hypertension
is more prevalent than previously recognized in patients between 7 and
18 years of age.