Symptom and description

A good night's sleep is important for your functioning and well-being. However, too much sleep can be a problem. One side effect of cancer and cancer treatment is sleeping too much. This is called hypersomnia, which means "too much sleep.''

If you have hypersomnia, you have difficulty staying awake when you want to and try to. You may sleep 10 hours at night, but still be unable to stay awake during the day. Hypersomnia is different from fatigue. Fatigue is the feeling of being tired, but able to stay awake if you try. If you sleep more than 10 hours at night, or if you are unable to keep from falling asleep during the day after a full night of sleep, you may have hypersomnia.  The most common causes of hypersomnia are your treatment or your mood.

Learning needs

You will need to recognize the symptoms of hypersomnia, how to describe them, and when to report them to your doctor. During a 3-week period, you may notice the following symptoms:

  • 10 hours or more of sleep at night

  • Problems staying awake during the day


This sleep problem is hard to prevent if it is due to your treatment.


If your sleep problem is due to your treatment, your doctor may want to prescribe medication to help you stay awake. If your sleep problem is due to sadness or personal problems, your doctor may either prescribe medicine or refer you to a counselor.

These tips may help you manage hypersomnia: 

  • Exercise every day

  • Maintain a regular sleep regimen, with the same wake-up and bedtime every day

  • Do things you enjoy that require your full attention

  • Avoid foods that make you sleepy

  • Avoid alcohol

Today's Interactive Tools
Related Items

The third-party content provided in the Health Library of phoebeputney.com is for informational purposes only and is not designed to diagnose or treat a health problem or disease, or replace the professional medical advice you receive from your physician. If you or your child has or suspect you may have a health problem, please consult your primary care physician. If you or your child may have a medical emergency, call your doctor or 911 or other emergency health care provider immediately in the United States or the appropriate health agency of your country. For more information regarding site usage, please visit: Privacy Information, Terms of Use or Disclaimer.