Low blood pressure (hypotension) - Symptoms and causes

OverviewLow blood pressure is a condition in which the force of the blood pushing against the artery walls is too low. It's also called hypotension.Blood pressure is measured in millimeters of mercury (mm Hg). In general, low blood pressure is a reading lower than 90/60 mm Hg.What's considered low blood pressure for one person might be OK for someone else though. Low blood pressure might cause no symptoms that you notice. Or it might cause dizziness and fainting. Sometimes, low blood pressure can be life-threatening.The causes of low blood pressure include dehydration and other serious medical conditions. It's important to find out what's causing low blood pressure so that it can be treated, if needed. TypesTypes of low blood pressure include: Orthostatic hypotension, also called postural hypotension. This is a sudden drop in blood pressure when standing up after sitting or lying down. Causes include dehydration, long-term bed rest, pregnancy, certain medical conditions and some medici...