Medical resident work hours refers to the (often lengthy) shifts worked by medical interns and residents during their medical residency. As per the rules of the Accreditation Council for Graduate Medical Education in the United States of America, residents are allowed to work a maximum of 80 hours a week averaged over a 4-week period. Residents work 40–80 hours a week depending on specialty and rotation within the specialty, with residents occasionally logging 136 (out of 168) hours in a week. Some studies show that about 40% of this work is not direct patient care, but ancillary care, such as paperwork. Trainee doctors are often not paid on an hourly basis, but on a fixed salary; in some locations, they are paid for booked overtime. Limits on working hours have led to misreporting, where the resident works more hours than they record. Medical resident work hours have become a hot topic of discussion due to the potential negative results of sleep deprivation on both residents and their patients. According to a study of 4,510 obstetric-gynecologic residents, 71.3% reported sleeping less than 3 hours while on night call. In a survey of 3,604 first- and second-year residents, 20% reported sleeping an average of 5 hours or less per night, and 66% averaged 6 hours or less per night. In a recent landmark study published in May 2021, the World Health Organization and the International Labour Organization estimated that globally in 2016, more than 745,000 persons died as a result of having a heart disease event or a stroke attributable to having worked long hours (here defined as 55 or more hours per week), making exposure to long working hours the occupational risk factor with the largest disease burden. Causes of high workloads Medical residencies usually require lengthy hours of trainees. Trainees are traditionally required to be present for set shifts, with the ending time of the shift dependent on momentary circumstances. The flexibility of this system makes it easy to abuse. Junior doctors often lack bargaining power and have difficulty changing employers. This leaves them with little say over their working conditions. Critics of long residency hours note that resident physicians in the US have no alternatives to the position that they are matched to, meaning residents must accept all conditions of employment, including very long work hours, and that they must also, in many cases, contend with poor supervision. This