Sleep disorders in night and shift workers


Human behavior and biological rhythms

The human being is designed to work during the day and rest at night, sleep is one of the basic human needs; while we sleep, it decreases: blood pressure, heart rate and other functions “slow down” so that our wonderful brain is in charge of “coordinating the maintenance and repair” of our body, that is, important physiological functions are performed during sleep . Biological rhythms have been fundamental to our evolutionary development, while circadian rhythms are what is called the “body clock” that determines our sleep patterns.
The constantly moving society requires people to work while many sleep at night, in developed countries, it is estimated that approximately 20% of the population works night shifts . This is the case of hospital personnel, as well as other health units, supervisors, surveillance teams, transporters, auditors and telephone operators, among others. The patterns constantly disturbed wake-sleep in night and turnicidad workers are linked to significant morbidity so called increasing attention from health professionals.
The night is an aggravating factor in health in itself , when we add to this a work shift, it has more negative consequences on the quality of life of people. In addition to the fact that there are greater occupational and health risks. Fatigue, chronic fatigue and drowsiness increase the risk of accidents in night workers and with constant shift changes, being 2 times higher than day workers; while the aging process can be 5 times greater than that of a person who works during the day. It should be taken into account that many night workers carry out other tasks during the day that prevent them from getting adequate rest.

Shift-work changes

The circadian rhythm is essential to determine sleep patterns, to define every 24 hours when we sleep and when we wake up, it is programmed through the light-dark cycle. In people with shift work rotating, sleep-wake pattern can be altered as well, so often have disorders of the circadian rhythm associated with the change of assigned shift, especially workers in their role, the night included, this It happens because when their biological clock was just getting used to the established shift, they change it, forcing the person’s body to make changes in sleep-wake patterns again, preventing the body from restoring itself at night. They may have symptoms similar to those of circadian dysrhythmia or “jet-lag ”: daytime fatigue, drowsiness, insomnia and gastrointestinal problems

Frequent disturbances in sleep continuity

  1. Shorter duration of sleep.
  2. Sleepiness at times when they should be “functional” to work, study or carry out daily activities.
  3. Insomnia.
  4. Reduction of alertness in waking periods.
  5. Circadian dysrhythmia or “jet lag”.
  6. Alterations in the sleep-wake pattern:
  • Delayed sleep pattern.
  • Advanced sleep pattern.
  1. Sleep-wake circadian rhythm disorders associated with work shifts.

How is the disorder evaluated?

There are some assessment tools to determine the duration and impact of sleep disorders such as:

  1. Epswort Sleepiness Scale (ESE).
  2. Insomnia Severity Index (ISI).
  3. Pittsburgh Sleep Quality Scale (PSQI).
  4. Multiple Sleep Latency Test (TLMS).
  5. Vigil Maintenance Test (TMV).
  6. Record of actigraphy with polysomnography.

Why does night work cause so much fatigue?

During the day and night brain wave activity patterns change, night workers often experience fatigue , which can become chronic. Because the work is carried out in a period of deactivation. When a person is exposed to light, even if it is artificial before 5 in the morning, the body can experience it as if instead of a “morning awakening” it was a “sunset”, because its “biological clock” is out of adjustment.
Why does the body of human beings when they sleep during the day not have an equally restful sleep and restoring, physiologically speaking? When night workers want to rest they finally find a series of stimuli in the environment that do not allow them to have such a restful sleep.
What are some daytime stimuli that make it difficult for the night worker to rest? The circadian “alert” state is stronger during the day, so we tend to pay more attention to certain environmental stimuli such as light, aromas, noise: telephone, mobile phones, traffic … All of these, as well as sounds coming from home and from the outside of a world in constant motion, important factors affect daytime sleep.

Suprachiasmatic nucleus (NSQ) and circadian rhythms

In the medial hypothalamus , we can find the suprachiasmatic nucleus (NSQ), which primarily regulates circadian rhythms, promotes the production of melatonin through the pineal gland, is in charge of adjusting our biological clock, through the light information received by the retina . The light emitted by compact fluorescent lamps (CFL) is highly damaging, due to ultraviolet C radiation with short wavelength, which can cause deterioration in proteins, DNA (Deoxyribonucleic Acid) of the eyes, the skin, affects the electromagnetic field of the person and also generates greater photosensitivity.
Night workers can be affected in different ways. First, about sleep-wake patterns, but also many of those who suffer from sleep disorders due to night work or due to frequent work often develop problems at a social level , sometimes there are inescapable social commitments, including family members, the divorce rate it is approximately 50% higher in people with night shifts. Often they don’t get enough rest, so they can have major mood swings, a common one being depression as well as anxiety disorders .

What are the possible biological impacts on night workers?

What rhythm does your life follow? Chronic lack of sleep tends to increase the risk of diabetes, cardiovascular disease and obesity “

People who have sleep disorder due to night work or due to turnicity, have a five times greater risk of suffering from metabolic syndrome (MS) , the WHO (World Health Organization) tells us that it is enough to classify it as MS, when a subject manifests simultaneously:

  • Insulin resistance.
  • High-density lipoprotein levels below recommended.
  • Changes in blood glucose levels.
  • Arterial hypertension (HT).
  • Overweight, obesity, or prominent abdomen.
  • Triglyceride numbers above normal.

Possible cognitive-behavioral manifestations in night workers

People with unusual shift work syndrome experience significant disturbances in neurophysiological measurements of attention and memory. Gumenyuk et al., 2014.

Night workers have a 2.5 times higher risk of presenting psychiatric disorders , a higher prevalence of suicidal ideas has also been observed, as well as in the use, abuse and dependence on: hypnotics, antidepressants, anxiolytics, analgesics and gastric protectors. The cognitive-behavioral problems that occur most frequently among night workers are:

  • Emotional Affective Disorder or Emotional Affective Disorder (SAD, Seasonal Affective Disorder )
  • Burnout syndrome (Occupational Burnout ).
  • Asthenia.
  • Irritability and lack of emotional regulation .
  • Difficulty making decisions.
  • Emotional lability or sudden mood swings
  • Memory and attention problems.
  • Neurasthenia.

10 strategies to adapt circadian clock in night workers

If you work night shifts, try to prepare yourself to do your job properly, try to do your job in good spirits, anyway you are already putting your heart into it! Your body requires extra energy and vital resources; By resting during the day, there is little chance of repairing the harmful effects that lack of nighttime sleep causes.
Have you paid attention to the biological rhythm that you emit? Remember that biological rhythms make us adapt as organisms to certain conditions, they depend on everyday phenomena that affect us such as temperature, climate and the amount of light. You can follow these strategies to have a better daytime rest:

  1. Get a check-up at least once a year and follow the medical recommendations.
  2. Take a daytime nap , less than 30 minutes before starting the night shift.
  3. Food hygiene : No matter how sleepy you are, do not delete any food and try to ensure that they are quality food, although the safest thing is that on night shifts, you want or are encouraged to eat foods with high calorie content and little nutritional value Remember that your body needs quality food to maintain your health, that’s why, even if your brain screams at you: Sleep! at the end of your shift, try to nourish your body soon with easily digestible food, not eating well and sleeping could easily become a habit, the health consequences would be very harmful.
  4. Keep your body well hydrated .
  5. Perform physical activity suggested by health professionals at least 5 times a week for 30 minutes, if it can be outdoors and taking a little sun, it is better.
  6. Cognitive-Behavioral Therapy (CBT): to have more rest, you can learn progressive muscle relaxation, visualization and breathing exercises, among others.
  7. Stimulus control techniques : use earplugs, a comfortable mask, heavy curtains or blinds, maintain a pleasant and adequate climate to rest, establish specific times, places and routines for sleeping.
  8. Avoid consuming energy drinks , alcohol, tobacco, and other drugs to stay “awake.”
  9. Stay away from bright screens at least an hour before bedtime: the light they emit and visual stimuli run counter to internal circadian physiology.
    • Reduce or limit the use of social networks before going to rest.
    • Turn off your mobile or disable notifications. Keep it at least 3 meters away from your body while you sleep.

In most countries, not taking into account all the risks to workers’ health caused by having night shifts, but you can do it yourself. If you suspect that you may have a sleep disorder, start keeping a dream diary , where you record the hours you sleep and wake up, it can be very helpful for your diagnosis and treatment with a health professional, who will recommends attending as soon as possible if you have trouble resting.


Please enter your comment!
Please enter your name here