There are various causes for a bloody nose, some of which include a nasal fracture, exposure to dry air or cold climates, nasal allergies, and chronic sinusitis. High blood pressure or hypertension may also cause recurrent nose bleeds. Sometimes, especially in young children, nose-picking or placing a small object inside the nostrils can also cause a bloody nose. Certain forms of cancer, primarily leukemia, has been known to cause nosebleeds as well.
A bloody nose that emerges from the front of the nasal passages is referred to as an anterior nosebleed. This is the most common form of a bloody nose. This typically occurs from a contact injury, such as a blow to the nose when a blood vessel is injured. Bleeding can be controlled by applying pressure, typically by pinching the nostrils shut for a few minutes.
Posterior nosebleeds are less common, and typically are caused by medical conditions. Hypertension, also known as high blood pressure, can cause posterior nosebleeds. With a posterior nosebleed, the flow of blood can be heavy. A bloody nose originating from an artery in back of the nasal passages may require emergency treatment if it cannot be controlled.
Individuals suffering from chronic sinusitis may suffer from minor nosebleeds occasionally. This may be due to the sinus and mucus membranes becoming overly dry from nose blowing and other irritants. Stuffy nasal passages may also cause a bloody nose. This is typically not a serious condition and can be treated at home.
In some cancer patients, particularly children with blood disorders such as leukemia, frequent nosebleeds may occur. Red blood cells are typically compromised, and white cells malfunction in leukemia patients. An inability to clot normally can result in a bloody nose that is difficult to stop.
Blunt force trauma is another typical cause of a bloody nose. In cases of orbital bone fractures or a broken nose, blood vessels may rupture, causing a nosebleed. Even without broken bones, bleeding from the nose may occur from the force of a blow.
Critical head injures that cause bleeding in the brain may also produce bleeding from the nose. In severe head injury cases, the patient may have bleeding from the ears as well as the nose. In such cases, increased pressure on the brain may cause swelling and bleeding that emerges from the nose.
Certain medications, such as aspirin, may produce nosebleeds in some individuals. Other blood-thinning prescription medications also may cause nosebleeds. This is due to the body's inability to produce clotting while using the medication.