Treatment

Hypersomnia During Cancer Treatment

Choose a preferred language


What is hypersomnia?

A good night's sleep is important for your functioning and well-being. But too much sleep can also be a problem. One side effect of cancer and cancer treatment is sleeping too much. This is called hypersomnia. Hypersomnia that's linked to chemotherapy treatment often improves after treatment ends.

Hypersomnia is different from fatigue. Fatigue is the feeling of being tired, but able to stay awake if you try. If you have hypersomnia, you have trouble staying awake when you want to and try to. You may sleep 10 hours at night, but still have trouble staying awake during the day. This sleep problem can be caused by cancer treatments or other medicines.


Causes of hypersomnia

Cancer-related hypersomnia may be caused by:

  • Low levels of red blood cells (anemia).
  • Depression.
  • Anxiety.
  • Pain.
  • Hormone changes, such as hypothyroidism.
  • Certain prescription or over-the-counter medicines. These include chemotherapy, antinausea medicine, sedatives, antihistamines, pain medicines, and antidepressants.


Symptoms of hypersomnia

You may have hypersomnia if you have these symptoms for 3 weeks or more:

  • 10 hours or more of sleep at night
  • Trouble staying awake during the day despite a full night's sleep


Managing hypersomnia

The treatment for cancer-related hypersomnia depends on the cause. If your sleep problem is due to your treatment, your doctor may want to prescribe medicine to help you stay awake. If your sleep problem is due to depression or stress, your doctor may prescribe medicine or refer you to a counselor or therapist.

These tips may help you manage hypersomnia:

  • Exercise daily in the morning or early afternoon instead of near bedtime.
  • Keep a regular sleep schedule, with the same wake-up and bedtime every day.
  • Do things you enjoy that need your full attention.
  • Don't eat heavy meals or foods that make you sleepy during the day.
  • Don't have alcohol or caffeine.
  • Get bright sunlight during the morning.

Featured in

Date Last Reviewed: 09/01/2025

© 2026 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare provider's instructions.
user headset icon

Need Help? We're Here for You

Our Member Services team is here to help you understand your benefits, find care, or resolve concerns.

1-800-510-9132
quit smoking icon

Call NC Quitline

Need support to quit smoking, vaping, or to quit other nicotine products? You can receive support including medicines free of charge:

1-800-784-8669
car and bus icon

Schedule Transportation

Need transportation to a doctor's office, pharmacy, or other covered healthcare service? Contact us to arrange your ride.

1-800-510-9132
Stethoscope icon

Provider Directory

Need to find a provider like a Primary Care Physician, Specialist, OB/GYN, or a Psychiatrist? 

Provider Directory
Related Articles
Read article
Oncology
Soft Tissue Sarcoma: Chemotherapy

Chemotherapy (chemo) uses anticancer medicines to kill cancer cells. Learn how it's used to treat soft tissue sarcoma.

Read article
Oncology
Soft Tissue Sarcoma: Treatment Questions

Talking with doctors about your cancer can be overwhelming. It can be hard to take in all the information. It helps to be prepared. Here are a list of questions to ask your doctors.

Read article
Oncology
Procedures for Nonmelanoma Skin Cancer

Surgery is one of the most effective and common procedures for nonmelanoma skin cancer. It can remove the cancer with minimal impact on nearby tissue. Read on to learn about the different surgical and nonsurgical choices.

Read article
Oncology
Enteral and Parenteral Nutrition Support for Adults With Cancer

Cancer and cancer treatment can make it hard to get the nutrition the body needs. Learn about two types of nutrition support that can help people meet their nutritional needs during cancer treatment.