How do i fix a thumb injury?

Depends on injury: If you injured your thumb you should be evaluated by a physician. Xrays should be ordered to rule out a fracture. If it is a dislocation then wearing a splint will be necessary. If it is a sprain it depends which ligament is sprained or torn because sometimes surgery is required. Better to get evaluated by an md for hand injuries rather than just wait to see if it heals on its own.

Depends on type: Thumb injuries include fractures, contusions, ligament or tendon strains and/or dislocations. Each of these is often treated with a period of some type of immobilization (cast, splint or brace) for a variable amount of time (1-6 weeks, typically). It's very important to seek treatment from a qualified specialist, as the thumb is such an important digit used in almost all activities of daily living.