I don't know about the "almost passing out" part, maybe you have low blood sugar, but the dizziness is normal. It's often caused by hypotension (low blood pressure). Hypotension is normally caused by rising too quickly from a squatting or sitting position which is called postural hypotension. Or maybe it's from the way you are sleeping. When your uterus grows, it starts to put pressure on your aorta & vena cava (basically your spine and spinal tissues). This can be alleviated by sleeping on your side rather than your back. The term for this is supine hypotension. Your caregiver should often take blood samples, and can tell you if you are anemic. Hope this helps. Goodluck!

~kate~