Vasomotor rhinitis is a nonspecific disorder that is caused neither by infection nor allergy but rather by an imbalance of the autonomic nervous system with a preponderant action of parasympathetic fibers on nasal blood vessels. Rhinitis during pregnancy appears to result from the increased production of estrogen; increased estrogen levels caused by treatment, puberty, or liver disease may also cause rhinitis. Nasal saline mist, antihistamines, and topical corticosteroids are recommended; intranasal corticosteroid injections are also useful but must be administered under expert care. Rhinitis medicamentosa results from overuse of topical vasoconstrictors, which produce a rebound phenomenon. Rebound can also result from numerous medications, including antihypertensive preparations that reduce catecholamine levels, antidepressants, antipsychotics, and tranquilizers. Management of rhinitis medicamentosa consists in limiting the use of vasoconstrictors to no more than 3 days and giving the patient saline nasal sprays, daytime oral vasoconstrictors, and nocturnal antihistamines. Corticosteroids, preferably topical nasal steroids rather than even a short-term course of systemic administration, should also be used.