Low blood pressure

Low blood pressure is generally considered a blood pressure reading lower than 90 millimeters of mercury (mm Hg) for the top number (systolic) or 60 mm Hg for the bottom number (diastolic).

What's considered low blood pressure for one person might be OK for someone else. Low blood pressure might cause no noticeable symptoms, or it might cause dizziness and fainting. Sometimes, low blood pressure can be life-threatening.

The causes of low blood pressure range from dehydration to serious medical conditions. It's important to find out what's causing low blood pressure so that it can be treated, if necessary.