If you hit your wrist, the top two suspicions given your symptoms would be either a fracture
/break of the wrist or a bone bruise
. The wrist is composed generally of the two long bones of your forearm (radius and ulna) and eight small pebble-shaped wrist bones (carpal bones). As these bones are interconnected with ligaments, you could think of your forearm almost as an eye-shaped ring in which the two points of the ring act as hinges, and represent the elbow and the wrist itself. Each time you rotate your wrist/forearm, you can imagine the ring rotating on these hinges. Hence, any disruption of that ring in the form of a break/fracture results in pain with rotation of your wrist/forearm because the ring now moves in discontinuity. Even in the case of a bone bruise, where the "ring" remains intact, rotation can also be painful, albeit less so than a fracture/break. While a fracture/break can often result in deformity this is not always the case; swelling occurs in both settings. If your pain is severe, this would seem more consistent with a fracture, in which case you should see an orthopaedic surgeon
for formal x-rays and evaluation. You should not put any weight on the effected hand/forearm. You may require anything from a splint/cast/brace to surgery. In the case of a bone bruise, this will usually get better with rest and a period of non-weight-bearing. If these conditions should ever really apply to you or someone you know, please contact your physician or call 911 in cases of emergency.