What Are the Causes of Nose Bleeding in Humans?

Nosebleeds can be sudden and disturbing. While they are generally not a symptom of a larger problem, nosebleeds can startle young children and adults alike.

Physical Trauma

• Nosebleeds are often caused by a direct hit to the nose. Some nosebleeds are caused by light blows that happen to cause the septum to be jammed and cause bleeding in the inner nasal cavity.

  Blood will generally flow from one nostril in the case of a nosebleed due to a hit to the nose, but can occasionally flood the nasal cavity with blood and make both sides bleed.

  Picking the nose can damage the thin skin within the nose and cause bleeding from the capillaries near the surface of the skin.

Cold and Allergies

• Colds and allergies can cause irritation of the nasal tissues through repeated blowing and wiping. Nosebleeds can result when the nasal tissue is dry.

  Some sinus medications can cause dryness in the nasal passages, allowing the thin skin to crack and bleed easily.

  Dry conditions such as dry heat in the summer or central heating in the winter can cause sinus and nasal tissue dryness and bleeding.

Other Physical Causes

• Occasionally tumors behind the sinuses can cause enough pressure to cause a nosebleed. Nosebleeds with pain or that are accompanied by pain in the sinuses or headaches should be investigated by a doctor.

Excessive Bleeding

• Hypertension only rarely causes nosebleeds, though it can make nosebleeds last longer and add to the blood loss. Blood thinners and doses of aspirin thin the blood and allow more of it to pass through the nose during a bloody nose.

When to See a Doctor

• If nosebleeds are frequent, long in duration, or are happening often--see a doctor.

  If a nosebleed involves an excessive amount of blood, dizziness or nausea, emergency treatment may be necessary.