Thank for asking to HCM, This could be arthritis
changes of single joint, go for x-ray of your wrist, if turns negative then just do nothing to your wrist, have simple splint
, apply some local analgesic
cream, take rest of few days can take the anti inflammatory drug Ibuprofen
would be nice, and if x-ray shows some arthritic changes then discus it with Doctor,, Have a nice day.