A family history of hypertension can influence the behaviour of blood pressure during ergometric stress test (EST) in normotensive subjects, so that it is also used in the assessment of risk of hypertension. To evaluate the relationship between parental history and blood pressure values during exercise, 57 consecutive adolescents (aged 10-16 years) were studied. Out of them, 25 patients have not been considered because of the presence of organic pathologies of various nature that could interfere with the pressure behaviour. All patients underwent EST with a load increase of 25 W every 3 min until the maximal age-related heart rate. The patients were divided in 2 groups based on the presence (PH+ 13 patients, mean age 13 +/- 2 years) or on the absence (PH- 19 patients, mean age 13 +/- 2 years) of parental history of hypertension. No difference in body surface and maximum workload was observed between the 2 groups. Exercise test induced an increase in systolic blood pressure (SBP) both in PH- and PH+ patients, but no significant differences were found in any stage of the exercise in the 2 groups. Maximum heart rate (HR) was not different in the 2 groups and diastolic blood pressure (DBP) was substantially unchanged during exercise. The variation of SBP (delta SBP) between maximum stress and first, third, fifth and tenth min of the recovery phase were considered. Besides, 4 SBP indexes were deduced from the ratio of SBP values at the first, third, fifth and tenth min of the recovery by the SBP value at the acme of stress.(ABSTRACT TRUNCATED AT 250 WORDS)