Occasional bleeding from both nostrils, known as Epistaxis, can happen due to dry nasal passages, nose picking, allergies, sinus infection, high blood pressure, or irritation of the delicate blood vessels inside the nose. In many cases it is mild and stops on its own. Keeping the nose moist with saline drops, avoiding nose picking, and staying well hydrated may help prevent it.

Your nose blockage with AC exposure is likely due to allergic or non-allergic rhinitis, where cold, dry air irritates the nasal lining and causes swelling. Frequent use of decongestant nasal sprays can also cause rebound blockage if used for many days. Try using a saline nasal spray regularly, keep the room air slightly humid, and avoid direct AC airflow on your face. If symptoms persist, a doctor may prescribe an anti-allergy tablet or a steroid nasal spray for longer control. Avoid using regular decongestant sprays for more than 3-5 days continuously.