Get it x-rayed to be sure. When my daughter was 6, she fell at a roller skating party. She cried for 2 minutes, and then went back to skating. She was holding it against her tummy, and wouldn't let anyone touch it. It didn't look broken, and wasn't swollen. She had one little bruise on the inside of her wrist.
Ten minutes later my husband comes over holding his wrist. He wiped out and landed on his wrist. You could tell by looking at it that it was broken.
I took them both to the hospital, and they both came out wearing identical casts. They had broken the same bone on the same arm.
So there's the difference between a kid and an adult.