Shift Work Raises Your Stroke Risk

Recent research has revealed a surprising side effect of long work hours and shift work. Working night shifts or inconsistent shift schedules increases your chances of having a stroke.

This is not good news for any of us. Some industries are all about round-the-clock service. This makes shift work a reality for many people -from delivery drivers to health care providers to law enforcement professionals and emergency personnel.

Shift work and stroke

Researchers from The University of Michigan used data from the Nurse’s Health Study, acquired between 1988-2004. The researchers used that data to evaluate the health status of nurses who work rotating shifts. The researchers found that rotating night shift work was associated with a 4% higher risk of stroke for every 5 years of work.

Another group of researchers from Canada looked at rotating shifts of workers in varied jobs and, consistent with other studies, found an increased rate of heart attacks and strokes among shift workers.

Why can shift work cause stroke?

There are several ways that shift work increases your risk of stroke.

Altered metabolism

When your body experiences frequent disruptions in circadian rhythm, your hormones do not know how to adjust your blood sugar and your metabolic enzymes. Left in a state of confusion, your body holds on to harmful fats as a way to avoid would-be starvation.

Your blood cholesterol and fat levels may rise, even if you maintain a healthy diet. This can lead to blood clot formation, ultimately triggering a stroke.

Blood sugar

Your digestive enzymes that metabolize blood sugar do not know when to expect sleep and when to expect calories, and your blood sugar regulation can lag behind as your body responds to surging glucose levels when you eat – because your body cannot ‘learn’ to predict when your glucose levels will rise.

This can lead to a pre-diabetic state that harms blood vessels and increases the risk of stroke.


Our blood pressure regularly rises and falls throughout the day. When your sleep/wake cycle fluctuates erratically, your body’s attempts to regulate your blood pressure may be less effective than usual, leading to chronic hypertension, which is a major cause of stroke.


Maintaining a healthy lifestyle while living with an irregular schedule can be challenging. Inconsistent caffeine use can lead to headaches and stress, as well as insomnia. If you need to take prescription medications on a schedule, your fluctuating work hours can interfere with your medication schedule. Getting enough exercise and quite time can be a challenge when you do not have a regular daily routine.

What can you do?

Many jobs require round the clock shift work and long hours. Nurses, doctors, firefighters, law enforcement officers and other emergency response workers have to be available 24 hours per day. Given that few people want to work only nights, most people in these professions have to share and rotate in the night work. Other, non-emergency jobs often require rotating shifts and long hours to maximize productivity.

And, many night shift jobs do, in fact, pay better for work during the night because it is less convenient and harder to staff.

So, most people who work long hours or rotating shifts are doing it because of necessity, to avoid losing their job or to earn more money.

There are things you can do to minimize the impact of shift work and long hours.

  • Taking your medication as prescribed is important in preventing health complications.
  • Making sure to eat a healthy diet and get enough exercise is an important way to reduce the negative effects of shift work hours.
  • Maintaining strong, healthy, positive relationships with friends and family can be tough if you are tired and not available at the same time as people who work a regular schedule. But it is a necessary part of life that requires extra effort if you work irregular shifts.
  • Carving out time to relax and meditate or just to have quiet time can help you re-establish your sense of time when you are chronically living with irregular shifts.


Shift work and vascular events: systematic review and meta-analysis.Vyas MV, Garg AX, Iansavichus AV, Costella J, Donner A, Laugsand LE, Janszky I, Mrkobrada M, Parraga G, Hackam DG, British Medical Journal, July 2012

Rotating night shift work and the risk of ischemic stroke.Brown DL, Feskanich D, Sánchez BN, Rexrode KM, Schernhammer ES, Lisabeth LD, American Journal of Epidemiology, June 2009

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