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Cancer, Chemo and Insomnia: Why Can’t I Sleep?

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why you can't sleep due to chemo, cancer and insomnia Erwin Wodicka/PhotoSpin

Sleep disturbances are common in people with cancer — especially those who are undergoing chemotherapy or other types of treatment, or survivors who've been treated in the past.

Difficulty with insomnia, the ability to fall and stay asleep, is reported in 30 to 50 percent of all cancer patients, according to a recent study. Other studies say the rate may actually be much higher — 75 percent of all cancer patients reporting long and short term insomnia.

One thing’s for sure — the lack of sleep can make a difficult situation even more challenging.

Insomnia not only affects your quality of life. It can negatively impact your treatment and increase risks for other physical and mental health problems.

For example, cancer-related fatigue, daytime sleepiness (hypersomnia), anxiety and depression are commonly reported in people who experience sleep disturbances.

Women who are treated for breast cancer may be most affected, and often list sleep disturbances among the most distressing symptoms experienced during chemotherapy.

A joint study by researchers at Laval University Cancer Research Center in Québec, Canada, and the University of California-San Diego found “little distinction between daytime and nighttime activity cycles” in cancer patients prior to and during treatment.

This pattern indicates a disruption in circadian rhythms.

The master internal biological clock located in the brain helps regulate our body’s normal rhythms during the 24-hour cycle, from temperature and hormone levels to the natural sleep-wake cycle. Circadian rhythm disruptions may even contribute to cancer itself.

During chemo, our biological clock gets out of sync, especially during the first round which is most disruptive, according to the study. However, the longer the treatment goes, the more difficult it is to regulate your biological clock.

The authors stated that patients may need cognitive behavioral therapy or bright light therapy to prevent sleep disturbances from becoming chronic. Both types of therapy have been found to be beneficial for breast cancer patients and survivors.

Cognitive behavioral therapy for insomnia helps you identify and replace thoughts or behaviors that can cause or worsen sleep habits.

“Unlike sleeping pills, cognitive behavioral therapy for insomnia helps you overcome the underlying causes of your sleep problems,” according to the Mayo Clinic.

Bright light therapy is used to reset the biological clock that is off, to help restore healthy sleep patterns. Bright light therapy uses artificial light to expose your eyes to intense, but safe, amounts of light for a specific and regular length of time.

The time of day when the light is used will depend upon the disorder it is meant to correct, according to the American Academy of Sleep Medicine.

In addition to helping resolve insomnia, bright light therapy is used to correct Seasonal Affective Disorder. SAD is a type of depression that occurs in some people during fall and winter where natural sunlight is not available, and in people who suffer from insomnia related to shift work.

Lynette Summerill is an award-winning writer and Scuba enthusiast who lives in San Diego with her husband and two beach loving dogs. Besides writing about cancer-related issues for EmpowHER, her work has been seen in newspapers and magazines around the world.

Sources and more patient information can be found at:

”Breast Cancer Patients have Progressively Impaired Sleep-Wake Activity Rhythms during Chemotherapy.” Josée Savard, PhD. Loki Natarajan, PhD, Michelle B. Rissing, MA, Ariel B. Nelkrug, MS, Feng He, Joel E. Dimsdale, MD, Paul J. Mills, PhD, Barbara A. Parkerm MD, Georgia Robins Sadlerm PhD, Sonia Ancoll-Isreal, PhD. The Journal Sleep, Vol32, Issue 9. Accessed online 28 November 2012 at:

”Insomnia treatment: Cognitive therapy instead of sleeping pills.” Mayo Clinic. Accessed online 28 November 2012 at:

”Fatigue and Sleep during Cancer and Chemotherapy: Translational Rodent Models.” Maria Ray, Laura Q Rogers, Rita A Trammell, Linda A Toth.Comparative Medicine 2008 June; 58)3): 234-254. Published online 20008 June at:

”Bright light therapy.” American Academy of Sleep Medicine. Accessed online 28 November 2012 at:

Reviewed December 4, 2012
by Michele Blacksberg RN
Edited by Jody Smith

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We value and respect our HERWriters' experiences, but everyone is different. Many of our writers are speaking from personal experience, and what's worked for them may not work for you. Their articles are not a substitute for medical advice, although we hope you can gain knowledge from their insight.