Yup, I would agree it sounds like low blood pressure.
Whenever I get anaemic, my blood pressure drops and whenever I get too hot, hungry and have to stand for long periods of time, I get dizzy. Standing up quickly brings light-headedness, a bit of nausea, and loss of vision. Sometimes I've fainted. Best thing to do is get checked out. Don't know why you'd have low blood pressure. Take it easy when standing up. Steady yourself, take deep breaths. Make sure you are eating enough and often enough and try not to get over-heated.