I fell off my bike now my hand is swollen all the way up to my wrist?

See a doctor: Could be just strain from the injury or you may have a fracture. See a doctor and have an x-ray taken.

Fracture or sprain: If you fell and your wrist is swollen and hurts to move i would advise getting an xray. Right now would splint it...Can use anything rigid and wrap it with a shirt or cloth to keep it still. You may have broken your radius, ulna or one of carpal bones (scaphoid). Could be a bad sprain too but xray will help discern this better.