Rhinitis, << ry NY tihs, >> is an inflammation of the mucous membranes that line the nose. The inflammation increases the production of nasal mucus and can make breathing through the nose difficult. Rhinitis can result from infections, allergic reactions, and unknown causes. It occurs most frequently as part of the common cold, a viral infection. Many other cases result from hay fever. Certain chronic (long-lasting) forms of rhinitis can cause the mucous membranes to thicken or to wear away. See also Cold, Common ; Hay fever .
