The most common cause of a bloody nose is trauma, but it can also occur due to a disease, according to WebMD. Conditions such as high blood pressure can also contribute to nose bleeds.
Trauma can occur either inside or outside the nose, explains WebMD. A blow to the face, for instance, or excessive nose picking are common causes of nosebleeds. Even irritation from a cold may cause the nose to bleed.
It is less common for a disease to cause nosebleeds, states WebMD. One such condition is the inability of the blood to clot. This may occur due to taking blood-thinning medications such as warfarin or aspirin. Liver disease may also contribute to the inability of the blood to clot. Abnormal blood vessels in the nose and cancer can also contribute to nosebleeds, but these causes are rare.
Most nosebleeds heal quickly at home, but there are some situations where a person must see a doctor or seek out emergency treatment, notes WebMD. For instance, a person should see a doctor if nosebleeds happen with frequency and if nose bleeds occur along with blood in the urine or stool. Seek emergency medical services if bleeding doesn't stop after pinching the nose for 10 minutes, if having trouble breathing, if vomiting blood or if you have a fever.