What is fatigue | Association of Anaesthetists

Fatigue: are you at risk?

What is fatigue?

Fatigue goes beyond common 'tiredness'. Fatigue is the state where tiredness becomes overwhelming and isn't relieved by rest or sleep.

What causes fatigue?

Fatigue can be triggered, or increased, by a variety of factors including stress, poor diet and nutrition, lack of sleep and other lifestyle factors.

Within the NHS, high-pressure working environments, long working hours, sporadic shift patterns, night-working and a lack of appropriate rest can all contribute to a fatigued NHS workforce.

Fatigue is the subjective feeling of the need to sleep, an increased physiological drive to fall asleep and a state of decreased alertness.

Going beyond the call of duty

Lengthy shifts continue to be a reality for many doctors in training: a report from the Royal College of Anaesthetists found that 95% of anaesthetic trainees were regularly staying beyond the end of their shift to work. 

Despite guidance on rest breaks outlined in the New Deal contract, self-assessment of tiredness and fatigue risk management are not yet part of routine practice.

Lack of rest facilities

The abolition of 24-hour resident on calls has seen rest facilities removed from many hospitals. Less than a third of anaesthetic trainees who responded to the Association-led survey had access to a suitable rest facility, and of those who did, approximately 10% had to pay between £5 - £65 per shift to use them.

Patients at risk

In an aircraft emergency, the priority is to put your own oxygen mask on first before helping others. NHS services can only be safely delivered by paying attention to the same principle.

Patients are always best‐served by NHS staff functioning at their optimal level. A healthcare professional who has worked a 12 hour shift without a break is far from at their best, yet this practice is widely prevalent in today's NHS.

When we have been awake for 16–18 hours, our reaction times are similar as when blood alcohol levels are at the legal drink/drive limit. We process information more slowly; we adapt to new challenges less quickly. We make riskier decisions and, critically, our insight into how much fatigue affects us is also impaired. Errors in care and judgement become more likely.

The high-risk checklist


  • Have you been unwell or suffering from symptoms of pregnancy?
  • Has your health been put at risk by clinical work; e.g. needle-stick injury or risk of exposure to infectious disease?
  • Do you need to talk to the occupational health team?


  • Are you taking prescribed or over-the-counter medication that might be affecting you?


  • Are there work or non-work related factors that might affect your performance?
  • Do you need to speak to someone before going on or off shift?
  • Does the team need to debrief/give feedback?


  • Could there still be alcohol in your system?
  • Consider your consumption in the last 24 hours, not just the last eight hours


  • Have you had restricted sleep in the last two weeks?
  • Have you had restricted sleep for the last two nights?
  • Have you had trouble speaking coherently or keeping your eyes open?
  • Would a short sleep make you safer?


  • Have you had something to eat or drink? Do you need to?

If you have answered ‘yes’ to any of the above, don’t ignore it. Get help to Fight Fatigue. 

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