This morning, for no reason, I almost blacked out. Very lightheaded. While walking my dog, I felt nauseus and short of breath. Checked my blood pressure, 120/84, I have since almost passed out two more times (hours apart). I also sort of have waves of stomach cramps. I walk 3 miles a day, in good health, take Nia and hula classes 3 times a week. this is very weird. I take hydrochlorothiazide for blood pressure (25 mg a day)