Study Objectives: To measure differences in functional status between men and women presenting with sleep-related health problems. Methods: A retrospective clinical audit of 744 Australian patients across 7 private general practices between April 2013 and January 2015 was conducted. Patients completed an electronic survey as part of their routine consultation, which included the Epworth Sleepiness Scale (ESS), the Functional Outcomes of Sleep Questionnaire 10 (FOSQ-10), and other questions relating to the effect of their sleep problem. The proportion of males and females with ESS and FOSQ-10 scores associated with disorders of daytime sleepiness and burden of symptoms due to sleepiness, respectively, were compared, as well as reported differences between the sexes in memory, concentration, issues with relationships, feeling depressed, and trouble sleeping. Results: On presentation, females were more likely to have sleeping disorders associated with daytime sleepiness (median ESS score of 9 for females versus 8 for males, P = .038; proportion ESS > 9 was 49.0% for females versus 36.9% for males, P = .003). Women were also more likely to report an increased burden of symptoms due to sleepiness compared to men, as shown by lower FOSQ-10 scores (P < .001). Secondary outcome measures showed that females were more likely to feel excessively tired and depressed, have difficulties with memory and concentration, and have trouble sleeping at night. Snoring kept partners awake in roughly the same proportion of males and females, and a larger proportion of the partners of males were forced out of the room. Conclusions: Sleep-related health issues both manifest in and affect the lives of males and females differently. Sleep health professionals should recognize these differences on all levels of disease prevention and health promotion from patient education, to diagnosis and management to improve quality of life for those with sleep-related health problems. Keywords: ESS, FOSQ-10, functional outcomes, obstructive sleep apnea, sex differences, sleep health Citation: Boccabella A, Malouf J. How do sleep-related health problems affect functional status according to sex? J Clin Sleep Med. 2017;13(5):685-692.