A 42-year-old male presents to the emergency department with a complaint of a nosebleed that started about 30 minutes ago. The patient reports that the bleeding began spontaneously while he was watching television. He is otherwise healthy, with no significant medical history. The patient denies any trauma or recent upper respiratory infections. He works as an accountant and has not had any recent changes in his environment or exposure to allergens. The bleeding has been constant and involves the right nostril. He has tried pinching his nose and tilting his head forward, but the bleeding persists.

On examination, the patient appears anxious but is in no acute distress. There is active bleeding from the anterior nasal septum. No signs of significant bruising or hematoma are noted, and the rest of the physical examination is unremarkable. The nasal mucosa is dry, and there is no evidence of infection or deviated septum. The patient reports that he sometimes experiences nasal dryness, especially in winter.

The most likely diagnosis is epistaxis, likely due to nasal dryness, which is common in dry or cold environments. The patient is treated with nasal packing and given instructions to use a saline nasal spray and a humidifier at night to prevent future episodes. He is also advised to avoid vigorous nose blowing and to apply a thin layer of petroleum jelly to the inside of his nostrils as needed.