lefty wrist injury. i hit me forehand on the left side of my body and one-handed bh on the right side of my body. imagine mariano puerta, yeah, im like him.
If you're flicking your wrist any, then that definitely could be putting strain on it. If you're bending it at an unnatural angle and exerting force on it then that could be putting strain on it. Basically anything but a fixed wrist before, during, and all the way until just after contact may cause problems. This applies to both forehand and backhand.
Post a video of you hitting some forehands/backhands if you can, maybe you're unconsciously jerking it around? MTChong is right though, not enough info to properly diagnose as is.. Sorry
P.S. Fear the number of the beast, bookakaka