Women's CenterAllergic rhinitisAlso listed as: Hay fever; Perennial allergic rhinitis; Rhinitis - allergic; Seasonal allergiesSigns and SymptomsCausesRisk FactorsDiagnosisPreventionTreatmentOther ConsiderationsSupporting Research Allergic rhinitis is an allergic reaction that happens when your immune system overreacts to substances that you have inhaled, such as pollen.