What are the main factors associated with the cause of dizziness when waking up, or after any period of laying down.  The dizziness is not apparent until after a rest.At first, I thought it might be a sensitivity to red wine, but it is not alcohol related.  Could it be popcorn?? I am now associating it with movie popcorn being the only evening meal.
It is just postural hypotension I guess. As you have not mentioned your physical profile, I can't comment specifically. But in general when you stand up from sitting or more from supine(lying down) position, due to gravity your blood flow direct to lower limbs for a while and your brain deprive of fresh blood for fraction of seconds. But body can reflexively restore blood flow. When your lower limb veins valve are somewhat weak or muscle mass is low it can happen. You need to measure your blood pressure. If it is in lower normal range just increase your slat intake 3 gm/day. If your problem disturbing you and your routine a lot, please consult doctor.