Background: Sudden sensorineural hearing loss (SSHL) is an acute disorder whose origin is often unclear. A vascular disorder may be a causative factor. Objective: To determine whether hypotension influences the genesis of SSHL in healthy subjects. Design: To investigate the role of a 24-hour blood pressure (BP) profile in a population of young subjects with SSHL from January 1, 1996, to December 31, 1999, by a nonrandomized controlled trial. Setting: The Ear, Nose and Throat Section of the Department of Surgical and Anaesthesiological Sciences and the Department of Internal Medicine, S. Orsola Hospital, University of Bologna, Bologna, Italy. Patients: The study population consisted of 23 untreated healthy patients diagnosed as having SSHL compared with 20 age- and sex-matched normotensive control subjects. Both groups underwent 24-hour BP monitoring, and their BP profiles were analyzed and compared with routine BP values. The data were analyzed with the Statistical Package for the Social Sciences, version 7.1, and the results are expressed as mean SD. Main Outcome Measures: The mean BP values were expected to be lower in the study population. Results: The average clinic and ambulatory BP values were significantly lower in patients with SSHL, for systolic (clinic, P=.004; ambulatory BP, P=.02) and diastolic (clinic, P=.03; ambulatory BP, P=.03) values. The occurrence of persistent hypotension (the presence of >2 consecutive recordings of systolic BP of less than or equal to 105 mm Hg and/or diastolic BP of less than or equal to 60 mm Hg) was increased in the population with SSHL. Conclusion: Systemic hypotension must be considered as the possible cause responsible for the development of SSHL in young healthy subjects.