AimTo assess the incidence and associated risk factors of asymptomatic urinary retention in elderly women upon admission to the Internal Medicine department. MethodsTwo hundred and two consecutive elderly women (mean age 84.45.7 years) who were admitted to four Internal Medicine departments at a tertiary medical center were prospectively enrolled. All patients underwent post-void residual urine (PVR) measurements on the morning following the admission day. The measurements were undertaken by using a portable ultrasound bladder scan. Asymptomatic urinary retention was defined as PVR200ml without lower urinary tract symptoms, or abdominal pain, in two consecutive measurements. ResultsAsymptomatic urinary retention was diagnosed in 29 (14.4%) women (mean PVR: 353.1 +/- 155.2ml; range: 200-712ml). The mean age, prevalence of chronic diseases, and the use of opioid and antimuscarinic drugs were similar in women with versus without asymptomatic urinary retention. A binary logistic regression analysis showed that asymptomatic urinary retention was significantly and independently associated with low mobility, measured by the functional independence measure (FIM) scale (odds ratio=0.7, 95% confidence interval 0.6-0.9, P=0.026), and hypothyroidism (odds ratio=2.4, 95% confidence interval 1.0-5.8, P=0.049). Among 174 (86.1%) patients in whom thyroid-stimulating hormone (TSH) serum levels were measured, a statistically significant correlation was demonstrated between TSH values and PVR measurements. ConclusionsAsymptomatic urinary retention in elderly women upon admission to the Internal Medicine department is not infrequent and is independently associated with hypothyroidism and low mobility. PVR measurements should, therefore, be considered in all women with a low level of mobility and/or hypothyroidism upon admission to the Internal Medicine department. Neurourol. Urodynam. 36:794-797, 2017. (c) 2016 Wiley Periodicals, Inc.