Shift Work Sleep Disorder – Causes, Symptoms, Diagnosis and Treatment

Shift work sleep disorder (SWSD) refers to a difficulty falling asleep, staying asleep, or not getting restorative quality sleep for at least one month. In this article, we review shift work sleep disorder, its symptoms, causes, diagnosis and treatment.

Written by:


, Sleep Researcher
Last Updated: Thu, October 3, 2019
Fact checked by:

Marko Jevtic

, Sleep Specialist

Shift work sleep disorder (SWSD) refers to a difficulty falling asleep, staying asleep, or not getting restorative quality sleep for at least one month. This disorder is often compared to jet lag that occurs to people who are traveling between different time zones. Jet lag is characterized by fatigue and excessive sleepiness.

Not getting enough quality sleep can affect your overall health, mood, concentration and learning abilities, sex drive, mental health, and can lead to a series of medical conditions.

In this article, we review shift work sleep disorder, how it affects people and how to prevent it or treat it if you have already been diagnosed with SWSD.

What Is Shift Work

In the US, shift work is considered for any job that falls out of the regular nine to five schedule. It mostly refers to night or graveyard shifts, that start in the evening and span during the night, or it can also refer to continuous shifts that can last for an extended period of time, somewhere as much as 40 hours. There are also semi-continuous shifts, they are usually short, but you can do two or three of them each day. Continuous shifts are frequent in healthcare, law enforcement, security, firefighters, military, hospitality, pilots and aircrew industry and many more.

Most shift workers follow the same day to day schedule, and this is known as the same shift pattern. Multiple shift pattern means that people working certain jobs are changing shifts, and can work day or night shifts, depending on the schedule.

According to the Bureau of Labor Statistics (BLS) report from 2004, around 15% of workers in the US followed some shift work pattern.  4.7% of people reported to work evening shifts, 3.2% said to work night shifts, 3.1% reported working a multiple shift schedule, while 2.5% had a rotating shift schedule.

In many industries, jobs with irregular hours are standard so that shift work might be the only option. Some people who have kids find it easier to sync with them while working shifts. Shift work is usually paid more, due to not working regular hours, so people who seek a financial aspect of a job may find that tempting. Employers also love shift work, as that enables them to be active and profitable for 24 hours a day, so many will choose this option.

However, working shifts have been linked to a series of health problems and sleep disturbances. SWSD disrupts your circadian rhythm, that is in charge of telling you when is the time to do things during the day, and when is the time to go to sleep. Even though the circadian clock is built-in, and there are molecular mechanisms that keep it in place, our environment can significantly affect it. That is why maintaining a good sleep pattern is very important.

Symptoms of SWSD include headaches, excessive sleepiness and fatigue, insomnia, irritability, lack of focus, memory problems and many others. As a result, it can lead to some mental health problems such as anxiety and depression. Lack of alertness can lead to some work-related and non-work related injuries, mainly if you are operating heavy machinery or driving. Sometimes, the results can even be fatal.

How Shift Work Affects Sleep

Your body is in homeostasis, meaning it keeps all the inside processes and parameters inside some range. When some parameter falls out of that range, it says that something is wrong and it damages the body. Getting the regular required sleep lets our brain do a little housekeeping and keeps everything running smoothly.

Our brain has a built-in mechanism to control our circadian rhythm, which is crucial to our sleep patterns. Outside stimuli, such as light and temperature are sensors that give us important information about our environment. The brain processes this information and then regulates and synchronizes the hormone secretion with night/day cycle. The suprachiasmatic nucleus (SCN) is a part of the hypothalamus, and it controls many homeostatic processes, including the production of melatonin, a hormone that is in charge of feeling sleepy and falling asleep. Typically, melatonin is produced in the evening and throughout the night, making sure that you stay asleep during the night. But shift workers are required to sleep during the night, so different needs will change the patterns of melatonin production.

In humans, sleep consists of two different stages, rapid eye movement (REM) and non-REM (NREM) sleep. REM phase is usually when dreams occur. NREM sleep consists of three stages. First one is the transition between being awake and falling asleep, second is the stage of light sleep when your heart and breathing rate slow down, and your muscles relax. The third stage is characterized by the slow brain waves, deep relaxation, and that is when your brain does the maintenance, repairing itself, as well as muscles and other tissue in your body. This stage is crucial, and unfortunately, it is mostly disturbed by the shift work sleep disorder. That is why SWSD can lead to many health problems, as your body can not restore properly, and when this becomes chronic, medical conditions are inevitable.

SWSD can have different effects on people. Some are entirely unaffected by it, especially the “night owls,” while others have many consequences. However, there are some trends noticed.

It is advised that everyone should get seven to nine hours of sleep each day. However, shift workers reportedly get only five to six hours each day, which is one to four hours less than recommended. They also tend to work more than non-shift workers, which can additionally reduce sleep.


While signs of SWSD vary between individuals, here are some most common symptoms:

To make things worse, chronic SWSD has been linked to disrupted eating habits, leading to obesity, heart problems, and diabetes. Females with SWSD have also reported menstrual cycle problems. Lack of sleep also affects your immune system, making you more likely to get the flu, a cold, or some other contagious disease.

Mental health is also affected by SWSD, and if not treated it can lead to feelings of depression and anxiety. Shift workers often feel out of sync with their friends and families, which can lead to loneliness, and affect their relationships with others.


If you suspect that you are suffering from SWSD, pay a visit to your doctor. They will ask you a series of questions about your sleep patterns, disturbances, and work schedule. They’ll also need to know about your medical past, as well as medication use. Sometimes, you’ll need to fill out a sleep diary for a week or two to give them a better insight into your sleeping habits.

Since SWSD has some symptoms similar to other sleep disorders, doctors will need to cross out conditions such as obstructive sleep apnea (OSA) and narcolepsy. They might keep you for an overnight study, where they’ll monitor your brain waves, heart and respiration rate, body movements and snoring.


Shift work sleep disorder is mostly treated with some lifestyle changes. There are certain things you can do to get rid of the symptoms.

Firstly, talk to your supervisor about your shifts if you are working in an industry where you can’t take the usual nine to five working hours, limit your shifts to a maximum of 12 hours. Also, make sure not to do more than four 12-hour shifts before taking a rest of 48 hours, as it will help you recover and it will improve your concentration at work.

If you are on a fixed work schedule, try to go to sleep and wake up at the same time every day, and get at least seven hours of sleep each day. By doing this, your brain will change the production patterns of melatonin and adapt your circadian rhythm, which will make it easier for you to fall and stay asleep.

If you have a multiple shift pattern, consider taking naps before going to work. Naps can improve your alertness and energize you, so an up to 45 minutes snooze before work can go a long way. You can even consider taking a quick 20-minute power nap on a break if it is allowed. That will help you stay concentrated throughout your whole shift.

Some other things you can try to improve your condition are:

If these lifestyle changes don’t help, your doctor might prescribe you some medications or supplements to help relieve your SWSD. Some prescription drugs can be addictive and have adverse side effects in the long run, so doctors will mainly stick to melatonin supplements. They are natural, non-addictive and with fewer side effects in the long term.

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Dusan is a biologist, a science enthusiast and a huge nature lover. He loves to keep up to date with all the new research and write accurate science-based articles. When he’s not writing or reading, you can find him in the kitchen, trying out new delicious recipes; out in the wild, enjoying the nature or sleeping in his bed.

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