A runny nose, also known as rhinorrhea, is a common symptom characterized by the discharge of fluid from the nasal passages. It is typically caused by irritation or inflammation of the nasal mucous membranes, often due to viral infections like the common cold or allergies. The fluid discharged from the nose may be clear and watery initially but can become thicker and yellow or green in color as the body’s immune system responds to the underlying cause. In addition to nasal discharge, individuals with a runny nose may experience other symptoms such as nasal congestion, sneezing, itching, or postnasal drip. While a runny nose is often bothersome, it is usually self-limiting and can be managed with over-the-counter remedies such as nasal decongestants, antihistamines, saline nasal sprays, or steam inhalation. However, if symptoms persist or are accompanied by fever, severe headache, facial pain, or colored nasal discharge for an extended period, medical attention may be necessary to determine the underlying cause and appropriate treatment.