Lib is totally right, but I wanted to add something too. She might be taking her BP Meds, and accidentally taking more than prescribed. Sometimes, I forget if I have taken my Med, and take it again, If her Medication is new, you might want to talk to the Doctor to see if she can either take another Medication, or something less potent. Hypotention is only a problem if the Patient is dizzy, or lethargic after taking it. Or in cases of dehydration, like Lib said, or if they are in shock because of a medical condition, or trauma. When, and if you do go to the Doctor with her, bring all medications that she takes, even if it is RX'd by another Doctor, to include the over-the-counter one's. So the Doctor can see if any of the meds are making the others stronger, or weaker. The very best method of taking the BP is the good old fashioned Cuff, and Stethescope.