What causes nosebleeds? And why some people get them more than others.

Few injuries are as common and as frustrating as nosebleeds can be. They often begin with a painful injury followed by rushing to a nearby bathroom or sink while trying to keep one's nose covered and one's head tilted back. It's an experience that can be both embarrassing and disorienting, and the resulting mess and sometimes costly bloodstained shirt or other ruined clothing items only makes an already frustrating situation that much worse.

Though nosebleeds aren't entirely preventable as the dry climates and physical circumstances that lead to them can't always be avoided, understanding what causes them can be helpful in at least limiting their occurrence throughout one's lifetime.

What is a nosebleed? 

Medically known as epistaxis, nosebleeds are any kind of bleeding that occurs from the nose. This could be a barely noticeable drip appearing from one nostril or an abundance of blood emerging from both nostrils - an occurrence sometimes referred to as a "gusher." 

Nosebleeds happen because of "many tiny blood vessels inside our nasal cavities that can burst when irritated or dry," explains Dr. Neha Pathak, chief physician editor at WebMD and a former primary care doctor at the Department of Veterans Affairs.

What causes nosebleeds? 

While many things can contribute to these tiny blood vessels becoming irritated, injuries resulting from getting punched, knocked, or elbowed in the nose are among the most common. Running into another person or object often results in a bloody nose for the same reason. 

Nosebleeds can also be the result of someone blowing their nose too hard or because an infection or allergic reaction occurs. "Nose picking is one of the most common reasons for nosebleeds in children," adds Dr. Steven Maher, an emergency medicine physician at Mayo Clinic in Arizona.

Being in an especially dry climate also contributes to many people experiencing nosebleeds. "Your lungs prefer warm, moisturized air," says Dr. Todd Hamilton, an ear, nose, and throat specialist at Revere Health in Utah. He explains that in the front of the nose, along the septum which divides the nose in half, there's an area where several prominent blood vessels converge. It's known as the Kiesselbach’s plexus - named after the physician who first described it. "In a common nosebleed, this area dries out and causes one of the blood vessels to crack, which results in bleeding," Hamilton says.  

That drying out isn't as likely to occur in humid climates like Florida or Hawaii though, and is instead an occurrence that's more common in dry climates like Utah or Texas. Hamilton adds that certain medications or conditions can also put one at greater risk for nosebleeds, "especially when a patient is on a blood thinner or has high blood pressure, which is not controlled." Maher agrees, and notes as well that, in rare cases, "nose bleeding may also indicate a hematologic or bleeding disorder." 

Why do some people get nosebleeds often?

Conditions and medications like these help explain why some people get more nosebleeds than others. "Some folks might also get nosebleeds more often due to allergies or because their blood vessels are simply more fragile," offers Pathak. Other individuals might merely be more prone to bleeding complications generally. And children and athletes are known to get more nosebleeds than other people mainly because they more frequently make physical contact with their peers. 

For nosebleeds occurring among people living in dry climates, "keeping the inside of the nose moist with a little petroleum jelly can help prevent future leaks," advises Pathak. "But remember, gentle does it - there's no need to go exploring up there or to be blowing your nose super hard."