What could cause me to feel really light headed and nauses when i am standing? it also occurs while i am sitting at times

Hi, : Hi, if i understand you correctly, you sometimes feel lightheaded or nauseated when you stand up or sit up. Although i cannot diagnose you, this does sound like orthostatic hypotension. Sometimes when you get up, gravity causes our blood to pool in our legs, as a result, less blood is making its way up to the brain and you can feel lightheaded. Make sure you get enough liquids every day. Sometimes eater smaller meals more often can help. Get up slowly when you go from lying to sitting or sitting to standing (especially after eating). Ask your doctor to check over your medications, to see if any of them may be contributing to this.