Bleeding won't stop after 10 minutes of direct pressure. Looks like a broken bone or dislocated joint. Skin is split open or gaping and may need stitches. Large swelling is present. Blood that's present under a nail is quite painful.
Fingernail is torn from a crush injury or cut.
Dirt or grime in the wound is not removed after 15 minutes of scrubbing. Toe injury that causes bad limp or can't wear shoes. Age less than 1 year old. If You think your child needs to be seen. If You have other questions or concerns.