Why doctors are fighting over blood pressure guidelines

How low is too low? That's what physicians are debating after new advice for treating hypertension was issued in December. High blood pressure is defined as 140 mmHg over 90 mmHg, and for years, doctors have used that measure as the threshold for prescribing anti-hypertensive drugs. But based on the new recommendations, adults who are 60 or older can wait until their readings reach 150 over 90 or above to begin medication. After reviewing available evidence on the effects of blood pressure treatments, including adverse events, the Institute of Medicine's Eighth Joint National Committee (JNC 8) concluded that aggressive treatment can lead to lightheadedness, falls and fainting in elderly populations — so they advised loosening the guidelines for starting medication.