Are Night Shifts Hurting Our Health?

Car Crashes

A recent article and review in a medical journal, Anaesthesia, looked in to the effects of fatigue on Junior Doctors ( A survey of some trainees in the UK assessed the effects of fatigue and ways to understand the factors involved.

Over 84% of those surveyed reported feeling too tired to drive home after a night shift. Over half of respondents said they had experienced an accident or near miss whilst driving home from a night shift. They described accidents ranging from minor scrapes to much more serious write-offs. Incidents were also reported with those walking or cycling home. The National Sleep Foundation published an estimate that around 1 in 6 deadly car crashes in the USA are as a result of drowsy driving.

The use of caffeine to try to off-set fatigue during and after nights was reported in over 80%. The ability to get 30 minutes of uninterrupted sleep was reported in half or less than half of shifts for the majority of people.

As well as fatigue effecting driving ability, respondents reported effects in other parts of their life. Around 70% of people reported negative effects of fatigue on personal relationships, physical health and psychosocial wellbeing. Over half of people reported a negative influence of fatigue on the ability to do their job.

Shift Work Damaging Health?

It is estimated that over 3 million people (nearly 1 in 8) of UK workers engage in shift work, specifically night shifts ( The above study focused on trainee doctors in Anaesthesia. Night shifts, and shift work in general, no matter what the industry can be damaging to health. This will likely be of no surprise to people who have ever worked nights and shifts.

The diseases linked to night shifts are numerous.  They have been linked to diabetes, heart attacks, even strokes. They have even been linked to some cancers, as well as digestive problems and mental illness. It must be stressed here that these are only links – with no evidence that night shifts are a direct cause of the above conditions. There may be other factors involved. This is called association, different entirely to causation. Many other factors, such as lifestyle factors (smoking, exercise, alcohol intake, obesity) and other pre-existing diseases are likely to play a large role.

It isn’t known exactly how shift work is linked to these illnesses. It might have something to do with the bodies’ natural rhythm being disturbed. This has been suggested in a report by the British Medical Journal of Occupational and Environmental Medicine. There is something called the Circadian Rhythm. This is how the human body knows whether it’s day or night. It tells this using an internal body clock of sorts – triggered by light and other stimuli – to trigger sleeping, eating patterns, etc. This means it can lead to unhealthy choices – e.g. not eating the right foods at the right times.

Night shifts can also cause problems on a more personal level. They can contribute to problems fitting in family and personal life. Conversely, shifts can also offer opportunities to be more flexible with childcare or hobbies at less busy times.

There can also be problems getting enough good quality sleep during the day when on night shifts. This can lead to worsened fatigue and a worsening of the effects already mentioned.

Do Night Shifts Cause Breast Cancer?

Some claims, however, are changing. You may remember several years ago – it was reported that doing regular night shift for over 30 years increases the chances of developing breast cancer. This link was found in several international studies. However, more recent reviews have looked again at these original studies, along with new studies, and found that there is no link between breast cancer and night shifts. These have also suggested that more research is done to clarify the situation. This is summarised in a NHS review.

What’s the Cure?

So, now that there are indications that night shifts are bad for us – what can we do?

There is a lot of guidance for how to avoid the common pitfalls of night shifts and how to avoid the potential health effects. The National Sleep Foundation has provided a whole host of advice. Some of the key concepts include:

  • Limiting caffeine intake during night shifts
  • Have lots of healthy food around the house and at work
  • Drink plenty of water – keep hydrated
  • Avoid fatty/unhealthy foods as much as possible

This links with basic sleep hygiene advice. This includes ensuring the room is dark, keeping a regular sleep routine, not clock watching and avoiding phone/tablet screens for a period before bed.

The Royal College of Physicians has put together a booklet with guidance for doctors on night shifts. It covers many areas:

  • Safety before, during and after night shifts – travelling especially
  • Performing at a safe level
  • Optimising sleep
  • Keeping healthy – diet and exercise

Some of the important advice included in this booklet is to try to get adequate rest before the first night. This includes napping and eating and drinking to keep energy levels up. Exposing yourself to bright light during the shift will help to make you more alert.

It also covers making sure you are safe to drive after a night shift. As we have already seen it is common to feel fatigue and unsafe to drive after a night shift. In these cases it is advised to use public transport as much as possible. Alternatively, it is possible to find out about sleeping arrangements at your place of work if you feel it is unsafe to travel home. More guidance can be found on the DVLA’s (Driver and Vehicle Licensing Agency) website:

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Any opinions above are the author’s alone and may not represent those of his/her affiliations. Any comment is based on the best available evidence at the time of writing.  All data is based on externally validated studies unless expressed otherwise. Novel data is representative of the sample surveyed. An online recommendation is no substitute for seeing your own doctor and should not be taken as medical advice. 

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Further Reading & References


About rickjh7 (3 Articles)
A doctor currently working as a locum in South Yorkshire. Clinical interests are Acute and General Medicine with a particular interest in the physiology and psychology of health and illness. I also have a keen interest in medical education.

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