What are some of the signs of a broken finger?

Pain, swelling, loss. Of motion, deviation, rotation, stiffness, throbbing, numbness, discoloration, tightness all can be symptoms of a finger fracture. If one suspects a fracture, then elevation, ice , splinting and urgent evaluation is needed as many seemingly simple fractures in the hand require a detailed understanding of what to do to optimize healing and return of function.
Injury signs. Signs of a broken finger are largely the signs of any injury and namely swelling, pain, redness, and warmth of the area. Depending on where and how it is broken there may be obvious deformity of the finger as well. There may also be some numbness because of associated nerve injury.
Pain loss motion. There will be pain, swelling, decrease in finger motion and possibly a crooked deformity to the finger.
Pain & deformity. This can be associated with signs if deformity, dysfunctional grip or scissorimg of the fingers with open/close, pain, weakness, audible clicking, swelling, etc. An x-ray should be diagnostic. Occasionally an MRI is required for hairline fractures with no displacement.