High blood pressure (hypertension) is a condition where blood pressure consistently measures 130/80 mm Hg or higher. It’s often referred to as the “silent killer” because it usually has no noticeable symptoms until complications arise. Low blood pressure (hypotension) is a condition where blood pressure is consistently low, generally less than 90/60 mm Hg. If chrnoic, it can cause dizziness, lightheadedness, and fainting