I am not quite sure of the difference between "lightheadedness", dizziness and vertigo.
I think true vertigo is when your vision sees everything truly spinning and it's impossible to walk. I have had this and had to crawl to the bathroom. Usually lasts about 24 hours and cause often unknown although the feeling is it's related to an inner ear balance issue. My dizziness is not vertigo but a feeling in my brain that I am moving. "Things" are not moving like vertigo but my mind tells me I am moving (back & forth for example).
Is lighheadedness a feeling one is going to pass out? I suppose my dizziness can also be called lightheadedness as when it occurs I do wonder if I am going to pass out but nothing "goes black" for me. But regardless, it's truly concerning. In my case it is anxiety although I do take medication for it...as it's also related to my migraines.
And more oddly, I can never lie completely flat - say on an examination table or in bed. I feel "something" happens to my blood pressure and I do become - I suppose - lightheaded. My head must always be propped up on pillows even going into a MRI or CT scan for example. All a bit confusing...any thoughts?