It's pretty common to get hair clogs in the tub/shower. I had a nasty one in our shower a few weeks ago; the price one pays for having 3 long haired people in one household. It depends on the drain type. Is is just a shower drain with a strainer that comes off and then there's an open fitting? Or is is a tub drain with a mechanical drain (you move the little lever and the drain opens/closes. These are a little more complicated to work with...if you take it apart you may not get it back together! Have you tried a plunger over the drain? Can you access the drain lines? There may be a cleanout in the drain pipe. (A little plug you can take off to get the gunk out of the line.) If you can access the drain, a small "snake" or auger will clean it out. For a tub or shower drain that has a lot of twists & bends, a small, very flexible snake should work. You can usually buy a small one at the hardware or home improvement store. :-) Good luck!