Tilt your head back for a nosebleed

What actually happened

Two errors were bundled into one piece of folk wisdom. The head position is the dangerous one: blood running down the pharynx irritates the stomach, and swallowed blood is a reliable emetic, which is why the classic nosebleed story ends with someone throwing up. In a child or an unconscious person there is an aspiration risk.

The pinch location is the useless one. About 90 percent of nosebleeds come from Kiesselbach's plexus, a cluster of vessels on the anterior septum, low in the fleshy part. Squeezing the bony bridge compresses bone and does nothing to that plexus. You have to pinch the soft part, firmly, and hold continuously, because releasing every thirty seconds to look tears off the clot you just made.

The correction is not new science, it is anatomy that has been understood for a century, and it is in current guidance from the Red Cross, the NHS, and the American Academy of Otolaryngology. It stayed in circulation because it is the kind of thing you learn from a parent rather than a source, and because most nosebleeds stop regardless, so the wrong method appears to work.