This more severe type of nosebleed needs immediate medical attention. Nosebleeds are caused by the rupture of a small vessel in the nose due to pressure in the head. The other main cause is dryness of the inside of the nose. They are more common during cold weather, when heating dries out nasal passages. Other causes of nosebleeds are colds, high altitude, allergies and medications.
Nosebleeds can also result from a calcium deficiency.
Occasionally, nosebleeds may indicate other disorders such as bleeding disorders, cancer, high blood pressure or disease of the arteries. This is a disorder involving a vascular growth similar to a birthmark in the back of the nose. Doctors advise people with lower-septum nosebleeds to sit up straight and pinch the nostrils together firmly for 10 minutes. An ice pack can also be applied to the nose and cheeks. The pressure should then be relieved to see if the nose is still bleeding.