How common is it to have low blood pressure?

Probably is normal: It depends if you have symptoms or not, or if you are on medications to control elevated blood pressure, or if you have underlying cardiac conditions. For some underlying abnormal conditions: consider dehydration, heart failure, anemia, low thyroid, or low cortisol.

Sometimes: Low blood pressure is actually better in terms of decreased heart and stroke risk. Low blood pressure can be normal for individuals who can be genetically predisposed that way. Low blood pressure is not normal if you feel dizzy or lightheaded or feel like your heart is pounding all the time. Most common cause of low BP is dehydration, so the treatment is drinking more fluids.