Borderline hypertension is defined as mildly elevated blood pressure higher than 140/90 mm Hg at some times, and lower than that at other times. As in the case of white coat hypertension, patients with borderline hypertension need to have their blood pressure taken on several occasions and their end-organ damage assessed in order to establish whether their hypertension is significant.
People with borderline hypertension may have a tendency as they get older to develop more sustained or higher elevations of blood pressure. They have a modestly increased risk of developing heart-related (cardiovascular) disease. Therefore, even if the hypertension does not appear to be significant initially, people with borderline hypertension should have continuing follow-up of their blood pressure and monitoring for the complications of hypertension.
If, during the follow-up of a patient with borderline hypertension, the blood pressure becomes persistently higher than 140/ 90 mm Hg, an anti-hypertensive medication is usually started. Even if the diastolic pressure remains at a borderline level (usually under 90 mm Hg, yet persistently above 85) treatment may be started in certain circumstances