If you have had a runny nose and frequent colds since childhood, it is usually due to allergies or a sensitive nose. Keep your room dust-free, avoid cold air and strong smells, and use a saline nasal rinse to wash out allergens. Steam inhalation once a day also helps clear the nose. Eating warm foods, staying hydrated, and taking vitamin C can support immunity. If symptoms are frequent, an antihistamine or an allergy nasal spray (prescribed by a doctor) can give long-term relief.