my purple tang is almost dead

[Ryanst]

I just came home today and I found my purple tang stuck to the underside of my vortech. Its still alive and it doesnt look like anything got cut off, just has ridges where the gaurds are on it. I dont know if i should see if it will pull threw or put it out of its misery. Right now it is pale in color just laying on the floor of the aquarium breathing heavy.