If you or someone else has a deep cut, it's important to stay calm and administer first aid. HealthDay offers these suggestions.
Take action:
Hold a clean cloth or bandage against the wound and apply steady pressure; at the same time, hold the injured area above your heart (unless a limb is broken); if your bandage becomes soaked, leave it there and apply a fresh bandage on top of the old one; try to rinse the cut gently with tap water only – no antiseptics or soap; if after five minutes the cut continues to bleed, if the cut is very deep or wide, if it's located on the head, or otherwise looks serious, seek immediate medical attention.