Unilateral nasal discharge with blood may be due to dry rhinitis, nose picking bad habits, nasal septum deviation, nasal sinus swelling and so on. 1. Dry rhinitis: if you suffer from this disease, in the weather is too hot, low humidity, patients inhale dry air will cause nasal mucosa dry, dry nasal mucosa is more likely to rupture, the emergence of the side of the nose with blood. 2. Bad habits: If patients usually have the bad habit of picking their noses, it will also cause the nasal mucous membrane to break, and there will be unilateral nasal discharge with blood. 3. Nasal septum deviation: Nasal septum deviation is usually due to the abnormal development of the constituent bones of the patient’s nasal septum or due to external damage, the patient will have nasal congestion, unilateral nosebleed, headache and other symptoms, and some of the patients will show unilateral nasal discharge with blood. 4. Nasal sinus mass: Nasal sinus mass may be nasopharyngeal fibrous hemangioma or malignant mass, which may appear as unilateral nasal discharge with blood, such as malignant mass may be accompanied by nasal pain, nasal congestion, or cheek swelling and pain. Unilateral nasal discharge with blood may be caused by other reasons, it is recommended that patients seek medical examination as soon as possible to clarify the cause of the disease and then actively treat it to avoid delaying the condition.