Nature has a design for all living creatures. When one tries to override that design, negative effects often result. For humans, the normal pattern would suggest being awake and active during the day and resting or being asleep at night. If the normal pattern is challenged, there is significant evidence to suggest health issues may arise. For occupations like public service personnel or hospital workers, long-term night shifts present an opportunity for negative health effects. The negative health effects of working night shifts have been the fodder for many studies, with the near universal conclusion that working night shifts cause negative health results.

The negative health effects of working night shifts include a wide range of potential problems including:

1. eating disorders
2. increased stress levels
3. chronic fatigue
4. sleep problems
5. ulcers and other gastrointestinal problems

In addition, there is evidence of an increased level of cancer due to the interrupted production of melatonin, which naturally occurs during normal sleep cycles but which is inhibited when those sleep cycles are interrupted. That normal cycle, called the circadian rhythm, is key to the maintenance of health for most people. When the circadian rhythm is temporarily interrupted, the human body might be able to get through the experience with little effect, but when the interruptions are continuous, the odds of developing health issues increase dramatically.

Evidence further suggests that women working night shifts are prone to gender related health threats. Nursing professionals are prime examples of women with elevated risks of developing health issues. Irregular menstrual cycles are common in women working over-night shift schedules. Problems associated with pregnancies are also common. Low birth weight and delayed development of fetuses may be attributed to working night shifts.

Our culture requires that persons engaging in certain occupations be available for work at all hours. Fire fighters, police personnel, doctors, nurses and many service occupations are all subject to working overnight shifts. Many of these jobs may also require working irregular hours, which further serves to interrupt the circadian rhythms. Many emergency workers, for example, often work unusually long shifts, making it nearly impossible to experience regular sleep patterns. Those individuals are at an elevated risk and should take steps to mitigate potential negative health effects. Consulting a sleep specialist is strongly advised to reduce the potential risks of working night shifts.