My red eye tetra is not feeling well.?

He is swimming upside down. Actually he cant even swim. He tried to swim to the surface with his head down and then turns oven and falls back down to the ground. He is still breathing though. What is wrong with my tetra!!!
Answers:
Your fish is suffering from Swim Bladder Disease. This is common and pretty simple to cure. First thing you will want to do is a water change. We are talking a 30% change while siphoning clean about half of the gravel. (It is a good idea to alternate which half you siphon clean each water change) Then refill with tap water of the same temperature that has been treated for Chlorine, Chlorimine, and other toxic trace metals. Stress Coat is perfect for this and is readily available at the big box stores and your local Pet Store. Next step should be stop feeding the tank for 3-5 days. (Or until/if you see the signs you described go away) If after the 5 days, you see no improvement, do another water change (25%) and feed the ill fish a frozen (Not canned) pea which you have allowed to thaw. Remove the 'skin' of the pea and smash it; drop it into the water. This will act as a laxative and allows proper function of the swim bladder. (The organ which allows fish to remain upright, and controls their depth.) Help prevent a reoccurance by performing regular water changes and by not over feeding.
I hope this helps!
Jason C.