Objective: To identify the pathophysiological mechanisms of nocturia and the correlation of these mechanisms with nocturia severity.
Methodology: After approval by the local ethics committee, all patients with nocturia (≥1 nocturnal void/night) were included and filled the Overactive Bladder questionnaire, Nocturia Quality of Life, Incontinence Questionnaire - Male Lower Urinary Tract Symptoms (male), International Consultation on Incontinence Questionnaire - Female Lower Urinary Tract Symptoms (female) and 3-day frequency-volume chart. Patients were divided into three groups according to the severity of nocturia: group 1 consisted of patients with mild (1-2 voids/night), group 2 with moderate (3-4 voids/night) and group 3 with severe nocturia (>4 voids/night).