Nose Bleed... Nosebleeds can occur for various reasons, and from a variety of sites. The most common site of bleeding is from superficial blood vessels on the anterior nasal septum. Posterior nosebleeds are the most dangerous and difficult to control. The bleeding site is often related to vessels that enter the nose through the spheopalatine foramen. Bleeding here can be controlled with posterior packing or endoscopic vessel ligation. 1999 Peter Casano, M.D.