Objectives. Stress-related exacerbation of interstitial cystitis (IC) symptoms has frequently been reported. Previous research has found stress-related IC symptom exacerbation in an experimental model. However, this relationship has not been objectively examined with daily life stressors. We used a prospective daily symptom diary method to investigate the relationships among stress and bladder symptoms in patients with IC and age-matched healthy controls.Methods. Forty-five previously diagnosed female patients with IC completed a bladder symptom and stress diary nightly for 1 month; 31 female age-matched healthy controls completed a similar diary for 7 days. The symptom questions were modified from the Interstitial Cystitis Data Base study.Results. Patients reported greater mean daily stress, bladder pain, urgency, and daytime and nocturnal frequency than controls (all P values less than 0.001). Among all patients, a significant relationship between stress and urgency was observed. In addition, a significant relationship between stress and pain was observed among patients with moderate and severe disease. As the disease severity increased, more pronounced relationships between stress and the symptoms of urgency and pain were evidenced. Greater stress was associated with greater nocturnal frequency among patients with more severe disease. These stress-symptom relationships were not observed among the controls.Conclusions. Higher levels of stress were related to greater pain and urgency in patients with IC but not in the controls. In addition, the relationship of stress and these IC symptoms was stronger among patients with more severe disease. The results indicate that life stress is associated with greater IC symptoms, particularly among patients whose disease is not well controlled.