What are nosebleeds? A nosebleed occurs when the tissue lining of the nose breaks and blood is released. This tissue contains small blood vessels, called arterioles, which can rupture easily. A nosebleed is medically known as epistaxis. Nosebleeds are very common, and children between the ages of two and 10 and adults between 50 and 80 years seem to be most susceptible. The most common nosebleeds happen in the front (anterior) of the nose. Anterior nosebleeds flow down and out of the nose. These nosebleeds generally occur in the septum, which divides the nostrils. Anterior nosebleeds are most frequently caused by some type of trauma. The blood vessels in the septum can be broken by scratching with a fingernail or during a high-impact injury to the nose. Dry air can cause the septum lining to dry out and crack, which may also cause a nosebleed in the anterior of the nose. Anterior nosebleeds can be stopped by sitting upright to ensure that your head is higher than your heart. Breathe through your mouth instead of your nose and lean forward slightly to avoid swallowing blood. Using your thumb and index finger, gently pinch the soft fleshy part of your nose closed for 15 minutes. Nosebleeds in the back (posterior) of the nose are less common and potentially more dangerous. Posterior nosebleeds occur higher and deeper in the nose, causing blood to flow down the throat. A posterior nosebleed can also result from a blow to the face or nose. Stopping a posterior nosebleed may require the assistance of a health care provider. Frequent nosebleeds may be a symptom of a blood clotting disorder that is present from birth and should be discussed with your health care provider. Seek immediate medical care (call 911) for a nosebleed that occurs after a head injury, if the nosebleed lasts longer than 30 minutes, if you are vomiting blood or having difficulty breathing, or if you experience confusion or loss of consciousness even for a brief moment. Seek prompt medical care if you have recurring nosebleeds.