I am light headed and spacey all the time. I also have loose bowel movements two or three usually first thing in the morning. The light headed feeling is constant not episodic. I am not suffering from fatigue. I am not depressed.I have had loads of tests scans etc with no diagnosis. Can anyone shed any light on this. It is very disabling and preventing me from working, driving etc. Many thanks. Andrew

some meds can cause lightheadedness as a side effect, also perhaps some foods, smoking can make it worse

seems to be a mystery as to exactly what lightheadedness is, did the docs give you any explanation?
look up depersonalisation on the net, maybe it and lightheadedness are similar?

when lightheaded, squeeze your keys in your hand and concentrate on the pain, sometimes this stops it a while.

get some smelling salts from pharmacist and try them when lightheaded.