There are many irritants that may cause nasal congestion or a stuffy nose. Irritants like cigarette smoke, air pollution, pollen and pet fur may trigger allergy reactions causing inflammation in the nasal membranes. The common cold may cause congestion which may lead to a bacterial or viral sinusitis infection. Mucus membranes that line the cavities in your nose produce a combination of mucus and fluid designed to wash away impurities. When the nose dries, it impedes this important function. Our microbiome (good bacteria) helps to modulate the immune responses when there is an infection or inflammation and are a very important part of our makeup. Over use of anti-biotics are killing our.