Purpose Heavy drinking has been shown to disrupt sleep, increase sleepiness the next day, and produce symptoms collectively referred to as ''hangover''. A survey was conducted to determine the impact of heavy alcohol consumption on sleep, daytime sleepiness, and hangover severity. Methods N = 335 adults, experienced with alcohol hangover, completed a survey of sleep quality, daytime sleepiness, and hangover symptoms comparing a heavy drinking occasion with a non-alcohol occasion. Data from those who reported [5-h sleep on the alcohol occasion were compared to those reporting \5-h sleep. Results Participants consumed on average 22.4 (SD 16.8) alcoholic drinks per week. On their last heavy drinking session that produced a hangover, the number of alcoholic drinks they consumed equaled 14.3 (SD 8.2). Relative to a normal night of sleep, sleep quality was significantly worse after the last drinking session (p \ 0.006), and the following day daytime sleepiness was significantly increased (p \ 0.0001). When controlling for alcohol quantity, daytime sleepiness significantly correlated to overall hangover severity, whereas sleep quality and duration did not.Conclusion Heavy alcohol consumption significantly reduces sleep quality, and significantly increases daytime sleepiness the following day.