Nasal irrigation is a useful supportive treatment for the common cold, particularly for nasal congestion, sinus pressure, and thick mucus. Saline rinses help flush out mucus, allergens, and irritants, which can improve breathing and reduce post-nasal drip. While it does not treat the underlying viral infection, it can significantly improve comfort and symptom control. It is important to use distilled, sterile, or previously boiled and cooled water to reduce the risk of infection. Nasal irrigation can also be beneficial in bacterial sinusitis, where it may help clear secretions and support overall treatment.