Common causes of nosebleeds include dry air, nasal irritation or inflammation (for example from allergies or infection), local trauma such as nose picking or injury, and less commonly bleeding disorders or medications that affect clotting. Most nosebleeds are minor, but you should seek urgent medical evaluation if the bleeding is heavy, continues for a long time, you feel faint or short of breath, or you are taking blood-thinning medications.
For occasional, mild nosebleeds, general supportive measures to reduce nasal dryness and irritation (for example using a humidifier and avoiding nose picking) may help. If nosebleeds recur, are frequent, or are accompanied by other concerning symptoms, make an appointment with your primary care provider or an ear–nose–throat (ENT) specialist for further evaluation. Emergency medicine can assist with sudden severe or uncontrolled bleeding.