Which statement about shift work's impact on sleep is true?

• A. Shift work can disrupt sleep schedules.
• B. Shift work does not affect sleep.
• C. Shift work always improves sleep.
• D. Shift work affects only daytime workers.

Answer: (C)

Shift work disrupts sleep schedules. Our bodies are wired to a day–night pattern, with sleepiness naturally rising at night and alertness higher during the day. Working night shifts or rotating shifts pushes sleep into times that clash with this rhythm, making it hard to fall asleep, stay asleep, or get enough restorative rest. Daylight exposure, noise, and activity during the day can fragment daytime sleep, leaving workers fatigued and less alert on duty. This effect isn’t limited to daytime workers; any schedule outside the natural night, including evenings or nights, can disturb sleep. It’s not true that shift work always improves sleep—most people experience poorer sleep quality and shorter sleep duration at least some of the time, especially when schedules change or are inconsistent.