In the past year, I've had two episodes of fainting (syncope?). Each took place after suddenly rising from sleep at night to respond to my husband in a hospital bed at home (has a brain-related diagnosis). Never fainted before, but the first time I took about 3-4 steps before "fainting', landing on the floor and my head hitting the floor. The 2nd time i actually was almost outside of our bedroom before fainting, again landing on the floor and my head hitting the floor. Could this be from dehydration or low blood sugar. I am petite, weigh 85 lbs., and probably don't drink enough water.