What first aid is given to a person whose nose is bleeding?

Use your thumb and index finger to pinch your nostrils shut. Breathe through your mouth. ... Pinching sends pressure to the bleeding point on the nasal septum and often stops the flow of blood. To prevent re-bleeding, don't pick or blow your nose and don't bend down for several hours after the bleeding episode.
www.mayoclinic.org/first-aid/first-aid-nosebleeds/basics/art-20056683