There is no definitive general limit , but even a minimal set of numbers above the norm can have serious consequences, including stroke and cardiac arrest. If you don t have medical coverage, consider the alternatives; A simple thing like munching from one to three stalks of celery per day, and drinking lots of fresh, clean, (preferably distilled) water, with just a half-a-pinch of sea salt in it, has been shown to significantly reduce blood pressure in many persons, often in as little as a few days, and there are no adverse side effects associated with this method, in contrast to the many adverse side effects associated with the majority of pharmaceutical-based remedies. I m not a licensed physician, and as such, I can t legally offer medical advice, but I ve been involved in alternative medicine for the better part of 17 years now, and the celery and water system seems to be one of the best ways I know of, to naturally control high blood pressure, and do it quickly, safely, cheaply and effectively. Any doctor will also tell you to avoid stress which is one of the dumbest and most stupid statements, ever heard! People don t look for stress, but in most instances, it can t easily be avoided. If stress is being placed upon you by an employer, co-worker, spouse or family member, then get help ASAP, to eliminate this major cause of stress.