Re: Hurt hand
He may have fractured or broken a bone and only a vet visit for an x-ray to confirm yes/no and having a cast, if yes, is required.
My cats...if they were limping and allowing me to handle their limb, I'd wait and see if it was just sore, bone-bruised or strained. If not better after a day, vet visit. If my cats cry out when I'm handling a possible injury...vet visit, no waiting to see, the crying out tells me something is wrong and paining the cat.