Pediatrics 140 (3): e20171904, 2017. doi: 10.1542 / peds.2017 - 1904 Etiology of Hypertension in Children Hypertension may be Primary (no known cause, a diagnosis of exclusion) Secondary (caused by another disorder, eg, kidney disease) After age 6, primary hypertension is by far the dominant etiology, and this is even more true for adolescents.