You haven't provided any information about yourself, including age, any medication you are taking or medical history. How low is your BP and are you experiencing any symptoms? How long has your blood pressure been low for?
Generally speaking, the lower the BP, the better. Low BP
is only every a problem if it's so low that it's unable to push blood around the body sufficiently. If this happens you would be symptomatic with dizziness
If you have concerns over your BP, visit your GP. In the meantime, keep hydrated and change position slowly.