About Sleep and Breast Cancer

You may not have thought about it, but there seems to actually be a connection between sleep quality and breast cancer. Not only can better sleep help prevent breast cancer, but it can also be a helpful factor in healing your body if you already have breast cancer. If a breast cancer risk is a concern or if you’re a survivor, keeping sleep health at the top of mind may be crucial for you.

Not only can better sleep help prevent breast cancer, but it can also be a helpful factor in healing your body if you already have breast cancer.

Breast Cancer In The U.S.

Aside from skin cancer, breast cancer is the most common cancer in women, according to the American Cancer Society. Currently women have a 1 in 8 chance of developing breast cancer in their lifetimes. Men can also get breast cancer, though it’s less common. The National Breast Cancer Foundation says that only 1 in 1,000 men will be diagnosed with breast cancer, but even though that number seems tiny, it’s a number to take note of, because it’s often assumed that breast cancer is not a cancer men experience.  

Whatever your relationship to breast cancer may be, knowledge is power. Our goal is to provide this information to you in an easy-to-read format that you can take to your healthcare provider for further discussion.

What this article will cover:

Is Sleep A Breast Cancer Risk Factor?

For those who have cancer, a history of cancer, or have had breast cancer surgery, it’s hard to not constantly have it at the forefront of your mind. Whether it’s what you eat or how much sleep you’re getting, it can all be related back to your health. In fact, a lack of sleep has been proven to be related to cancer, according to Johns Hopkins Medicine. In their studies, they discuss how “disruptions in the body’s ‘biological clock,’ which controls sleep and thousands of other functions, may raise the odds of cancers of the breast, colon, ovaries, and prostate.” Getting the proper amount of sleep can aid in healing your body if you do have cancer, as well. 

Ahead, we’ll break down how sleep is related to breast cancer specifically to help you understand the connection between the two, and how important a good night of sleep is to your health. Our goal is to provide base information for you to use as a starting point, and discuss with your doctor or sleep specialist. Above all, we want to help you develop the best sleeping habits you can.  

Image: Shutterstock/Iryna Inshyna

Sleep Quality and Cancer Risk

Sleep quality in general has been linked to breast cancer. In fact, studies have shown that poor sleep or not enough sleep is a definite breast cancer risk factor. A 2018 study, discussed in Science Today, showed that women who functioned “better at the beginning of the day than the end of the day have a lower risk of breast cancer.” It’s important to know that it’s both quality and quantity of sleep that are at play here.

Too Little Sleep

There are several factors that play into quality sleep, whether it be sleep latency or the amount of quality sleep you get. A small study was done on postmenopausal women to see if too little sleep had an effect on breast cancer, the study concluded that it did. The results read, in part, “people who don’t get enough sleep tend to have lower melatonin levels. Lower melatonin levels may lead to patterns of breast cell growth and repair that make breast cancer more likely to develop.”

“People who don’t get enough sleep tend to have lower melatonin levels. Lower melatonin levels may lead to patterns of breast cell growth and repair that make breast cancer more likely to develop.”


Melatonin is a hormone naturally produced by your body and it regulates your sleep-wake cycle, also known as your circadian rhythm. When your melatonin levels are off, it’s possible you can experience poor sleep. Though some people equate this with insomnia, it’s completely different. A melatonin imbalance is about your sleeping cycles more than general sleeplessness. Some doctors have also linked melatonin to cell growth and repair, which is why it’s an important factor in breast cancer risks. The previously cited study noted that lower melatonin levels could lead to breast cell growth and repair, making breast cancer more likely to develop. Again, though, this is science that needs much more research done to prove a more concrete link. 

Too Much Sleep

There’s also been a link between getting too much sleep and a risk of breast cancer. Though this may seem counterintuitive, a study did show a correlation. According to research, “an increased risk trend was found between sleep duration and breast cancer; our study also indicated that, compared to women with a normal sleep duration, women with a longer sleep duration might have a significantly increased risk of breast cancer; this was not observed among women with a shorter sleep duration.” So if you find yourself exhausted or sleeping longer than a recommended amount of time, you should bring this up to your doctor and make sure there are no underlying causes for the tiredness.

Night Shift Work

Even something like your work schedule can have an impact on your breast cancer risk. Working night shifts goes back to that melatonin issue we previously discussed. Working night shifts for a prolonged period of time can throw off your circadian rhythm. Forcing your body to adapt to working nights part of the week and go against its natural state of being can throw off all your hormones, which in turn, can lead to cancer cell growth, according to a few studies that have been done. 

Sleep Apnea As A Breast Cancer Risk Factor

Sleep apnea is a condition in which your breathing starts and stops while you’re sleeping. It is a very serious sleep disorder, and even more so if you have a history of breast cancer. 

Studies have shown that obstructive sleep apnea (OSA) is linked to breast cancer. One study in particular used the Korean National Health Insurance database to examine sleep apnea among women and how it relates to breast cancer. The study was done from 2007 to 2014, and the results are as follows: “in this study, breast malignancy incidence in OSA patients was significantly higher than that in control individuals. Moreover, there was a significant increase in breast cancer incidence in OSA patients aged ≥65 years.”

It’s difficult to pinpoint exactly what the link between sleep apnea and breast cancer is. One of the doctors who worked on a study about it told Science Daily that more research needs to be done to figure out the connection. What we do know is that obstructive sleep apnea causes your throat muscles to relax, and in turn, narrows your airways. Because you can’t take in enough air, the amount of oxygen in your blood dips, and generally your brain wakes you up. It makes for an unrestful sleep and is hard on your system. As we’ve already discussed, taxing your system in any way is not good for a person with a history of cancer.  

Addressing Sleep Apnea

If sleep apnea is a concern for you, it’s something to discuss with your doctor, as it’s a severe sleep disorder that needs to be carefully managed. Many people who suffer from sleep apnea use a CPAP machine to regulate their breathing patterns. Your doctor may also want to run a sleep study on you to see what’s actually happening while you’re sleeping, but together you can work out a remedy for the sleep apnea. 

If you have a history of cancer and you’re finding yourself suffering from sleep apnea, it’s crucial to do everything you can to make sure you regularly get a good night’s sleep. Once you and your doctor have had a conversation about managing sleep apnea, there are a few things you can do at home to better your sleep health. 

  • Yoga: Not only is yoga a relaxing exercise that can put your mind at ease before sleep, but it also helps you regulate your breathing. By training yourself to breathe in a certain way while you’re awake, it can help your body continue this healthy pattern. 
  • Take a look at your weight: Weight does play a part in your sleeping patterns. Overweight people tend to suffer from sleep apnea more, so speaking with your doctor about weight loss may help.
  • Avoid drinking and smoking: Alcohol and tobacco won’t help you at all if you have a history of cancer, and they especially won’t help you sleep. Both substances can relax your throat muscles and lead to worse sleeping problems, so cut both out to see if it helps.

The Importance Of Sleep During Cancer 

You’re probably familiar with insomnia — the inability to sleep. And if you’re a breast cancer survivor, you may already have intimate knowledge of what it’s like to live with insomnia. Actually, about 80% of cancer patients experience insomnia, much more than the general population. 

About 80% of cancer patients experience insomnia, much more than the general population. 

Cancer can also affect your circadian rhythm. When your circadian rhythm is off, you might find yourself struggling to fall asleep when you want to, or wake up on time when you’re expected. 

Insomnia During Cancer Treatment

Insomnia, unfortunately, is incredibly common among cancer patients. A 2012 study found that breast cancer treatments cause insomnia, as “chemotherapy and radiation therapy can disrupt sleep-wake cycles and interfere with sleep,” Eight Sleep reported. “A one-year, longitudinal study showed that both subjective and objective measures of sleep got worse with each cycle of chemo in 80% of women with breast cancer.”

Additionally, the side effects of radiation and chemo can also affect sleep. Symptoms like nausea, pain, and depression will all absolutely affect your sleep, and can be a contributing factor to your insomnia. Cancer patients also often experience hot flashes and anxiety, which can also make it very difficult to sleep. 

Tips for Healthy Sleep

Quality sleep is step one toward preventing breast cancer and for keeping your body healthy if you’re undergoing breast cancer treatment. A quality night of sleep is the foundation of a healthier body, so it’s important to try to get the right amount of quality sleep each night. Check out our tips for better sleep if you need even more ideas for a night of rest.

Practice Good Sleep Habits

Practicing good sleep habits will help improve both the quality and longevity of sleep. There are so many things you can do to improve your sleep, and some of them are incredibly simple. Try any of the following to see if they work for you:

  1. Create a routine: Put yourself on a schedule and stick with it. If you consistently go to bed and wake up at the same time every night, you can improve your sleep over time.
  2. Make your bedroom relaxing: Your bedroom should be the place you sleep. Create a calm oasis that’s inviting for sleep, and don’t spend time in there otherwise – this trains your brain to prepare for sleep when you are in that room. Consider adding pretty sheets, twinkle lights, an essential oil diffuser, or other items that make you feel rejuvenated while you rest. Make sure your mattress is new enough to be comfortable, as well as any pillows and bedding.
  3. Get at least seven hours of sleep: Take a look at your whole day to see how you’ll fit a solid seven hours of sleep in. It’s what you should aim for each night.
  4. Stay away from caffeine in the afternoon or evening: Caffeine after your morning coffee won’t help you come bedtime. Keep the caffeine to early in the day and stick to decaf after lunch.
  5. Limit bright lights: As you’re winding down later in the day, dim the lights around you. As the day progresses, the lights should get dimmer so that by the time it’s bedtime, you’re prepared for the cozy darkness.

You can also keep a sleep log to keep track of all your sleeping patterns, as well as your daytime routine to develop a full-fledged plan for better sleep health.

Natural Sleep Help

Natural sleep aids might be a route to try for sleep issues. They’re something to discuss with your doctor, but because they’re natural, they usually don’t cause any problems. However, you can never be too cautious, especially if you’re at risk of breast cancer or undergoing treatment. 

Some natural remedies you can discuss with your doctor to try include:

  • Melatonin: We’ve discussed how melatonin is a hormone your body produces and how it affects your sleep-wake cycle. You can also take melatonin supplements to regulate these cycles.
  • Magnesium: Magnesium is a natural sleep aid because it’s another substance naturally in your body that helps you sleep. When magnesium levels are low, it can lead to sleeplessness. 
  • Chamomile: Try drinking chamomile tea before bed. It’s known to relax your mind and body, which can help you sleep better.
  • Lavender: Either use a diffuser with lavender essential oil or use a lavender soap in the shower before bed to help induce sleepiness.
  • Valerian root: Take a valerian root supplement before bed to improve the quality of sleep.

Consider CBT for Persistent Sleep Problems

One option to try for sleeping problems is cognitive behavioral therapy. It’s a way of changing your actions to try to evoke an outcome, so it might include relaxation routines or sleep restriction. This is a method, though, that you should discuss with your doctor before trying out yourself at home.

Image: Shutterstock/BlurryMe

Final Thoughts

Whether you’re looking to lower your risk of breast cancer or help yourself better fight your current diagnosis, quality sleep is an important contributor for your overall health. Sleep builds the foundation of your day; if you’ve gotten a good night of sleep, it can improve your mood, your eating habits, and your overall quality of life. Honestly, there’s no reason not to try to improve your sleep health.  

If you struggle with sleep or want some guidance on how to sleep better, check with your healthcare providers for tips or advice on what you can do. Your doctors can make recommendations on how to get a better night of sleep or even point you in the direction of sleep aids that can help.