Differential Diagnosis for Bloody Nose

• Single most likely diagnosis
  • Dry air or nasal trauma: This is the most common cause of bloody nose (epistaxis), often due to minor injury or dryness in the nasal passages, leading to irritation and bleeding of the delicate blood vessels.
• Other Likely diagnoses
  • Allergies: Allergic reactions can cause nasal irritation, leading to increased blood flow and potential bleeding.
  • Upper respiratory infections: Infections such as the common cold or sinusitis can cause inflammation and bleeding in the nasal passages.
  • Hypertension: High blood pressure can cause blood vessels to become more fragile and prone to bleeding, including in the nose.
  • Nasal polyps or other anatomical issues: Abnormal growths or structural issues within the nose can irritate the nasal lining and lead to bleeding.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Tumor (benign or malignant): Although rare, a tumor in the nasal cavity or sinuses can cause bleeding and needs to be ruled out.
  • Coagulopathy (bleeding disorder): Conditions affecting blood clotting, such as hemophilia or von Willebrand disease, can lead to severe or recurrent nosebleeds.
  • Vascular malformations: Abnormalities in blood vessel formation can cause significant bleeding and require immediate medical attention.
  • Foreign body: Especially in children, the presence of a foreign object in the nose can cause irritation and bleeding.
• Rare diagnoses
  • Hereditary hemorrhagic telangiectasia: A genetic disorder characterized by the formation of abnormal blood vessels, which can lead to nosebleeds among other symptoms.
  • Granulomatosis with polyangiitis (formerly known as Wegener's granulomatosis): A rare autoimmune disorder that can cause inflammation and bleeding in the nasal passages.
  • Sarcoidosis: An autoimmune disease that can affect various parts of the body, including the nose, leading to bleeding and other symptoms.