Hundreds of business across the UK rely on 3.6 million shift workers to deliver their goods and services outside the standard 9-5 workday.

While shift work is par for the course in sectors like healthcare, hospitality and logistics, some people choose this type of schedule voluntarily because it lets them be more flexible.

But studies have repeatedly shown that it can have a devastating effect on your workers’ physical and mental health, as well as their social lives. How?

First, a quick biology lesson…

Our bodies have what’s known as a circadian rhythm. It’s a 24-hour internal clock that runs in the background of our brains, and it dictates when we feel alert and when we feel sleepy.

So if you’ve ever wondered why you’re always on the ball at 10am but feel like a zombie after lunch, it’s because of your circadian rhythm.

Not everyone is the same, of course. Some people are night owls while others are morning people. But you won’t experience big swings between alertness and drowsiness if you get a good night’s sleep.

How shift work affects sleeping patterns

When you work irregular hours, it causes a mismatch between the outside world and your internal clock. The brain sends signals that conflict with the activities you’re trying to do. So you’ll feel exhausted when you’re meant to be working and wide awake when you’re meant to be resting.

If the symptoms sound identical to those of jet lag, that’s because they are. The effects of working shift work are similar to travelling to San Francisco for work and returning to the UK for any rest days.

There’s even a name for the condition: shift work disorder.

At best, falling asleep on the job can lead to a loss of productivity. At worst, it can lead to a loss of life.

Effects on health

The list of illnesses and conditions that have been linked to shift work is long. Very long. Over the past few decades, studies from all over the world have shown that shift work increases the risk of:

• Fatigue.
• Insomnia.
• Gastrointestinal symptoms like upset stomach, nausea, diarrhoea, IBS, ulcers, constipation, and heartburn.
• Cardiovascular diseases like heart attacks.
• Diabetes.
• Metabolic syndrome—a combination of conditions like high blood pressure, high blood sugar, and unhealthy cholesterol levels.
• Obesity.
• Cancer.
• Depression and mood disorders.
• Problems with fertility and pregnancy.

Effects on social life

Aside from the myriad health risks, shift work can also take its toll on your employees’ social lives. Working nights on a regular basis can lead to your staff becoming isolated from their partners, not spending enough time with their kids, and missing important events like birthdays, anniversaries and graduations.

What you can do to help

Biologically speaking, working through the night is never ideal. And while this article makes for grim reading, there are ways you can minimise the negative effects of shift work on your staff. These include:

• Keeping your staff on a consistent schedule rather than changing it week in, week out.
• Stopping them from working too many night shifts in a row.
• Preventing them from working too many hours in a day.
• Letting them take regular breaks.
• Encouraging them to get a good night’s sleep and to take regular holidays.
• Discouraging the overuse of stimulants like coffee, over-the-counter medication and drugs.
• Making sure that your workplace has appropriate temperature and lighting, especially in the coldest winter months.

If you notice that shift work is having a negative effect on your workers, you should encourage them to seek medical help as soon as possible and change your workplace practices.