Latley I have not been my self, I have been feeling very tired, Hungry and thirty, and i have been needing to use the toilet alot. At least once a day my vision has been blacking out and then slowley fades back. This last from 2 - 6 minutes. When this happens I feel dizzy or my head hurts. This often happens and all so i start to see black speks that also fade, every now and again my right Knee begins to ache and that passes. Whats going on. I am a 17 year old female that weighs 55 kgs. Thanks