In the majority of patients with hypertension, no cause for the elevated blood pressure can be found and such individuals are defined as having ΓÇÿessentialΓÇÖ or primary hypertension. This is a familial condition, although the genetic basis for it is unknown; however, recent evidence suggests that the intrauterine environment may be important. Thus, blood pressure of adults in their fifties is significantly related to birth weight and placental weight: a small baby with a large placenta is more likely to have high blood pressure as an adult than is a large baby with a smaller placenta. Low birth weight is also a predictor of adult ischaemic heart disease and glucose intolerance.
