['Recently the Joint National Committee (7th report) introduced the term "pre-hypertension." Little is known on its prevalence in the general population.', 'To assess the prevalence of pre-hypertension in a large national cohort.', 'We analyzed the database of all > or = 18 year old members of Leumit Health Services, one of the four health management organizations in Israel, from which we retrieved the recorded blood pressure levels. Pre-hypertension was defined according to the JNC-7 criteria.', 'Of the 426,033 subjects 18.6% had a diagnosis of hypertension or used antihypertensive medications. Only 40.8% of the other 346,799 subjects had had their BP measured in the preceding 2 years. BP recording rates were higher in females than in males (45.1% vs. 36.3%) and higher in elderly subjects than in young subjects (56% aged 66-75 years vs. 32% aged 18-25). Pre-hypertension was observed in 80,625 (23.2%) of the 346,799 while only 56,113 (16.2%) had normal BP records. The prevalence of pre-hypertension increased with age (13.3% aged 18-25 vs. 44.8% aged 66-75), and was more prevalent in men than in women (24.0% vs. 22.5%).'] Is pre-hypertension a common phenomenon : national database study?