| Local | |
| Trauma | Nose-picking* Foreign body Blunt or penetrating facial trauma Child abuse Postoperative; Nasotracheal intubation Nasogastric tube placement |
| Mucosal irritation | Dry air* Allergic rhinitis Inhaled irritants/drugs (inhaled corticosteroids*, tobacco, cocaine heroin, volatile inhalants of abuse) Upper respiratory infection or systemic infection with nasal congestion Localized skin or soft tissue infection Colonization with pathologic bacteria (eg, Staphylococcus aureus) |
| Anatomic | Septal deviation or unilateral choanal atresia causing asymmetric airflow |
| Tumors | Hemangioma Juvenile nasopharyngeal angiofibroma (particularly in adolescent males) Pyogenic granuloma Rhabdomyosarcoma Nasopharyngeal carcinoma Inverting papilloma |
| Other | Increased nasal venous pressure secondary to paroxysmal coughing |
| Systemic | |
| Bleeding disorders | Inherited or acquired coagulation disorders, platelet disorders, blood vessel disorders (eg, hereditary hemorrhagic telangiectasia) |
| Medications | Aspirin, ibuprofen, anticoagulants (including rodenticides), valproic acid |
| Granulomatous disorders | Granulomatosis with polyangiitis (Wegener's), sarcoidosis, tuberculosis |
| Hypertension | Primary hypertension, secondary hypertension (renal disease, corticosteroids), increased venous pressure (exertion, superior vena cava syndrome) |
| Recurrent | |
| Usually related to recurrent/chronic nasal trauma (eg, nose picking) or irritation, but may be the presenting symptom of: Bleeding disorder Hereditary hemorrhagic telangiectasia Nasopharyngeal carcinoma Posttraumatic pseudoaneurysm of internal carotid artery | |
