A sprain is an injury to a ligament, the tough bands of tissue that connect bones together. Sprains can occur when the ligament is stretched or torn. The thumb is a common site for sprains, as it is involved in many everyday activities that can put stress on the ligaments.
Symptoms of a sprained thumb can include pain, swelling, bruising, and difficulty moving the thumb. Treatment for a sprained thumb typically involves rest, ice, compression, and elevation (RICE). In some cases, a splint or cast may be necessary to immobilize the thumb and allow it to heal.