Circulating DNA and mRNA for 11β-hydoxysteroid dehydrogenase (HSD) type II were measured in patients with hypertension and in healthy subjects. DNA and RNA levels in hypertensive patients and controls were quantified using real-time RT–PCR. Messenger RNA for 11β-HSD type II was significantly lower in the hypertensive patients (median: 0.18) (P= 0.032) than in healthy subjects (median: 0.42). Plasma DNA was also significantly lower (P= 0.016) in hypertension. It is suggested that measurement of mRNA for 11β-HSD type II in hypertension may identify subjects who may be salt-sensitive.