Nose bleeds. Nose bleed reasons: nasal congestion or nasal dryness, ^ blood pressure, excessive use of decongestants, being at ^ altitude, trauma to nose, nose picking, or blowing the nose hard. Bacterial & viral infections can ^ risk as well as bleeding disorders. Recurrent nose bleeds may be due to broken vessel in the nose. Alcohol / Cocaine abuse can cause nose bleeds, as can tumors.
Many causes. Nose bleeding can be caused by simple things like dry air, trauma, medications. But also more worrisome things like bleeding disorders, uncontrolled hypertension or non-healing nasal lesions/ulcers and possibly cancer. I recommend you visit your physician to determine the etiology/cause.