Scrutinise the injured thumb and determine if it was broken or sprained. You will need to rush the victim to the nearest hospital if the thumb was broken. However, if the thumb was only sprained, it is safe to tape it.
Swelling occurs almost immediately when a body part gets injured. The same holds true for an injured thumb. The best and most effective way of keeping the swelling in control would be to apply ice to it. Allow at least one hour for the ice to work on obvious swelling.
After the swelling has subsided a little, move on to the next step. To keep the thumb from moving needlessly, place a thumb splint, a tongue depressor, or a large wooden ice cream stick behind it.
Place gauze pads, 4-by-4 inch in size, around the thumb. Secure the gauze pads in place by wrapping cotton medical tape around the pads. Be sure to start at the wrist, wrapping all the way to the thumb. Avoid wrapping the injured area too tightly.
Do not cut off the tape. Extend it upwards instead so that the tape falls directly between the injured thumb and the forefinger. Wrap the tape around the thumb one more time and then tape the back of the hand. This will prove helpful for the purpose of immobilising the hand.
The pain caused by an injured thumb can be excruciating at times. If that is the case, administer one dose of doctor-recommended pain killer medication to the victim after you have taped the thumb. However, you will need to ensure that the person is not allergic to pain killer medicines in any way.