In general, people with a sprained thumb experience bruising, swelling or redness around the thumb, states the American Academy of Orthopaedic Surgeons. Additionally, a person may experience a weakened grip when holding items between her thumb and index finger.
People who think they may have sprained their thumb should see a doctor as soon as possible to ensure the sprain causes no permanent damage, states the American Academy of Orthopaedic Surgeons. If the sprain is mild enough, the doctor may simply immobilize the thumb with a splint or a cast for around three weeks. If the sprain is severe or the ligament in the thumb is torn, then surgery is usually the best option. The surgery usually consists of reattaching the ligament to the bone.