A nosebleed, known medically as epistaxis, comes in two forms: anterior and posterior. About 90% of nosebleeds are anterior, and start in the area between your two nostrils, called Kiesselbach's plexus, says Loftus. This area contains a lot of blood vessels little capillaries that keep the nostrils well supplied with blood, to warm the air you inhale. These can break open, creating a bleed that mostly pours from the nostril, though some blood may trickle into the mouth or throat, especially if you lean your head back.
The concept of saline nasal irrigation, or bathing the nasal passages with a saltwater solution, is thought to have been introduced as part of Ayurveda, an alternative medicine system that originated in the Indian subcontinent more than 5,000 years ago. Now, modern science is beginning to demonstrate that this ancient practice really does serve as a surprisingly effective shield against many of the seasonal bugs behind the common cold.