For over a year I frequently develop a fever (a few hours a day) , start feeling nauseous, get mild headaches, muscle aches, joint aches, and temporary dizziness ,LOSS OF SIGHT, and severe headache for a few seconds often when I stand up after lying down for more than half an hour.

I’m uses to being miss and under diagnosed. It took 5 years to be diagnosed with a bad case of equines (the worst the doctor had seen in 14 years. Yet three other doctors said it was in my head.
I know there’s something wrong because you dont just temporarily go blind after standing, even if it is only for a few seconds.
I’m 14 and live in australia if it helps.

been to my doctor heaps but he just dismisses it, despite being diagnosed with about three other conditions he dissmised. (equines, juvenile arthritis and patella femoral.

any ideas what could be causing it.

its definately not the heat, yet because it’s been winter so its only 19 or 20c but the heat makes it a LOT worse