21-year-old boy normal blood pressure

A 21-year-old boy's normal blood pressure is between 90-139mmHg systolic and 60-89mmHg diastolic.

Blood pressure is the pressure exerted by flowing blood on the walls of blood vessels. Hypertension is considered if systolic blood pressure exceeds 140mmHg and/or diastolic blood pressure exceeds 90mmHg on three non-same-day measurements. Conversely, systolic blood pressure less than 90mmHg and/or diastolic blood pressure less than 60mmHg is considered hypotension, which may be related to acute myocardial infarction, chronic malnutrition, chronic constrictive myocarditis, etc.

Since blood pressure values fluctuate due to strenuous exercise, emotional stress, alcohol consumption, etc., it is usually recommended to take three measurements at rest, not on the same day, to improve the accuracy of the results.