What can cause a runny nose and how can it be treated effectively?

A runny nose can be caused by Allergies, colds, or sinus infections. To treat it effectively, you can try over-the-counter medications like antihistamines or decongestants, use a saline nasal spray, or try home remedies like steam inhalation or staying hydrated. If symptoms persist or worsen, it's best to consult a healthcare provider for further evaluation and treatment.