After a pandemic-related dip caused by lockdowns, financial worries, and clogged supply chains, the night shift is roaring back into action as companies across the U.S. race to clear backlogs. And of course, there are millions of night shift workers whose hours increased during the pandemic — in some cases dramatically — such as hospital staff, police officers, firefighters, and truck drivers. Overall, an estimated 17.7% of the U.S. labor force, or about 29 million of the country’s approximately 165 million workers, works outside the hours of 6am and 6pm.

However, although the night shift can offer workers some benefits vs. their day shift colleagues — such as relatively higher compensation, fewer distractions, and a faster commute — there’s a hidden, potentially dangerous aspect that might add a new meaning to the term “the graveyard shift.”

Working the Night Shift May be Linked to Cardiovascular Disease 

Research¹ published in the peer-reviewed Cardiovascular Journal of Africa has concluded that shift work (which researchers defined as any work that is done outside of normal daytime working hours) may be associated with an increased risk of cardiovascular disease (CVD) for several reasons, including:

• Disturbed circadian rhythms
• Lifestyle changes
• Psychosocial stress   

In a separate study² published in the European Heart Journal, researchers concluded that individuals who work night shifts are at increased risk of developing atrial fibrillation (A-fib). This is an irregular and often very rapid heart rhythm (arrhythmia), which can lead to blood clots in the heart. A-fib also increases the risk of stroke, heart failure, and other heart-related complications.

Specifically, researchers found that individuals who worked night shifts on a usual or permanent basis had a 12% increased risk of A-fib compared to people who only worked during the day. The risk jumped to 18% after ten or more years for those who had a lifetime duration of night shifts. And among individuals who worked an average of three to eight night shifts a month for ten years or more, the risk of A-fib increased to 22% compared to daytime workers. 

Night Shift Workers Face Increased Risk of Hypertension

According to 2017 research published in the Annals of Environmental and Occupational Medicine:

Shift workers had a higher chance of hypertension than day workers do. Particularly, the longer the workers work continuously, the risk of hypertension getting higher.

A separate 2019 study published in the Journal of the American Heart Association concluded that “Shift workers with short sleep duration may be at risk for hypertension.”

And all you need to do is search online for ‘night shift and hypertension’ to find myriad other published, peer-reviewed research that in one way or another have found links between working the night shift and the increased risk of hypertension.

Women Who Work the Night Shift May Be at Increased Risk for Developing Cardiovascular Disease

For women working the night shift, the risk of developing CVD may even be higher. A study published in JAMA³ by researchers at Brigham and Women’s Hospital and Harvard Medical School found that women who worked more than 10 years of rotating night shift work had a 15-18% increased risk of developing coronary heart disease, compared to women who did not work rotating night shifts. Heart disease is already the #1 killer of women—accounting for more female deaths than all cancers combined. And according to the Centers for Disease Control and Prevention (CDC), 50% of women are unaware that heart disease is their gender’s number one mortality threat, accounting for more than 20% of all female deaths in the U.S. What’s more, women are 7X more likely to die from heart disease than breast cancer.

Heart disease kills more women than all forms of cancer combined.

Consider Offering a Digital Hypertension Self-Management Program for Night Shift Workers

Employers cannot eliminate the night shift — especially because, as noted above, some workers prefer this option. And due to various reasons, some workers have no other choice — the only time they can work is at night. However, given the potentially significant heart health risks, employers can and should try to help.

One of the studies noted above lays out three clinical implications of the association between shift work and hypertension:

• Monitor blood pressure routinely in shift workers
• Vary blood pressure monitoring to capture work days and non-work days
• Ask patients about shift work and their tolerance to shift work schedules

While this may sound like advice to physicians, thanks to the advent of cardiovascular digital therapeutics, employers can now take a more active, helpful role in improving the cardiovascular health of their most important resource. The first thing employers can do is to offer Hello Heart’s digital hypertension self-management program to their night shift workers (or to all workers with hypertension and those who are taking blood pressure medication).

The Hello Heart app, which comes with a free FDA-cleared blood pressure monitor, lets users easily track their blood pressure over time without the need for pen and paper — and users can securely share those readings with their physicians right from the app if they choose. The app also offers personalized nutrition and wellness tips and digital coaching that encourages healthier behavior, which can help people make changes that can reduce their blood pressure and subsequently reduce their risk of heart attack and stroke. And one of the most popular and convenient features of the app for people who are on blood pressure medication are the built-in medication tracking and reminders.

Choose a Digital Health Program That's Clinically Shown to Work

In a peer-reviewed study published in a JAMA Network Open, Hello Heart’s hypertension self-management program was clinically shown to reduce blood pressure.⁴ It also led to a 2X improvement in reducing blood pressure compared to other digital heart health options on the market.⁵

What Else Can Employers Do to Support Cardiovascular Health Among Night Shift Employees

The Society for Human Resource Management (SHRM) recommends the following:  

• Provide schedules that are as predictable as business needs permit.
• Limit the number of nights that are worked consecutively.
• When possible, avoid scheduling double shifts and overtime.
• Consider allowing long or frequent breaks.
• If possible, offer flextime and telecommuting.
• Install work-area lighting that is optimal for night shift workers.
• Designate areas and times for night shift workers to nap in the workplace.
• Train supervisors on how to identify chronically tired employees, and when to intervene.
• Provide health and wellness programs that are accessible at night and on weekends (note: the Hello Heart coaching app checks this box, as workers get personalized wellness tips on their smartphone and can access them whenever they wish, from wherever they are). 
• Encourage regular physical exams.
• Develop programs to screen for fitness for duty, as well as for sleep apnea and other sleep-related disorders.
• Where possible, offer transportation to and from worksites so that workers can have a little more time to relax — or sleep!

The Final Word

Hypertension, or high blood pressure, puts individuals at greater risk for heart disease and stroke, which are the first and fifth leading causes of death in the U.S.⁶ And research published in peer-reviewed journals suggests a link between night shift work and CVD. Employers are strongly encouraged to adopt the advice and best practices shared above — and to demonstrate that ALL of the members of the workforce, including those who work the night shift, are truly their most valuable asset.