Cancer fatigue: A common cancer side effect that is different for everyone

By Jessica Saenz

Cancer fatigue, also called cancer-related fatigue, is a common side effect of cancer and cancer treatment. As its name implies, an extreme sense of tiredness and lack of energy are key symptoms, but the condition can affect more than energy levels and make day-to-day life difficult.

"Cancer-related fatigue is overwhelming, and it is not resolved with rest or the normal things we do to make our bodies feel more energized," says Jenny Bradt, D.P.T., a Mayo Clinic physical therapist who specializes in cancer rehabilitation.

Symptoms of cancer fatigue include physical, emotional and cognitive exhaustion. These symptoms can begin at any point during your cancer journey and last weeks, months or sometimes years.

Everyone's experience with cancer fatigue is different. Personalized treatment programs that include comprehensive rehabilitation programs, including physical and occupational therapy, can help improve the condition.

Here's what you need to know:

Many factors contribute to cancer fatigue.

Cancer fatigue can be caused by your cancer, which can weaken muscles, damage organs or alter your body's hormones. Some cancer treatments can also cause fatigue due to damage from the treatment or its side effects.

Cancer treatment side effects associated with fatigue include anemia, pain, insomnia, poor nutrition, sedentariness, anxiety and depression. Hormone therapies for certain cancers and hormone-sensitive cancers can disrupt hormone levels, which also can lead to fatigue.

If you have conditions associated with fatigue in addition to cancer, known as medical comorbidities, these can sometimes worsen because of cancer and cancer treatment. "Pre-existing comorbidities such as anxiety, depression, hypothyroidism, chronic pain and sleep apnea can also play a role in cancer-related fatigue," says Touré Barksdale, M.D., a Mayo Clinic cancer rehabilitation and palliative medicine specialist.

Cancer fatigue is common, but the experience is different for everyone.

"There is no one-size-fits-all treatment because everyone experiences fatigue differently," says Dr. Barksdale. "Generally, everyone with cancer is going to have some degree of fatigue whether it's trouble putting on clothes, going to the bathroom, showering, going to the mailbox or doing things at work."

For some people, the mental and emotional effects of cancer fatigue can be just as distressing as the physical exhaustion. "Any cancer diagnosis brings a lot of uncertainty, anxiety, and sometimes depression," says Bradt. Changes in your ability to function due to cancer fatigue can sometimes worsen anxiety and depression.

Cancer treatment can also cause brain fog, also known as "chemo brain," which can include changes in your memory, thinking and focus. "Brain fog is a form of cognitive fatigue that is distressing and can interfere with the ability to continue normal social relationships with others and do the things that used to bring you joy," says Bradt.

Bradt says lack of motivation is another common effect of cancer fatigue. "If someone used to keep their house completely neat and tidy, and now they don't really care or want to do that — that is a side effect of fatigue, too."

If your mental or physical cancer fatigue is persistent and interferes with your daily life, it's important to take note of all your symptoms so your healthcare team can get a clear understanding of the best treatment plan for you.

Improving cancer fatigue with physical activity.

Bradt says some of her patients struggle to break the cycle of inactivity due to fatigue, while others struggle to return to their usual level of physical activity. Regardless of your starting point, consistent exercise that increases your heart rate can improve fatigue. "Most guidelines recommend 150 minutes of exercise a week, but we know that any amount of exercise per week is beneficial," says Bradt.

If you have difficulties with mobility or completing tasks, physical and occupational therapy can help you:

• Improve endurance and strength.
• Improve mobility and motor skills.
• Learn moderation and energy conservation.
• Improve your posture and comfort.
• Learn mindfulness practices to reduce stress.

"In physical therapy and occupational therapy, we look at what a person's exercise preferences are and what they like to do, and we work toward an exercise goal," says Bradt. "We use all the resources we have to address what is happening for people in that moment. As that changes, we readjust."

While physical activity can help improve fatigue, your path to recovery won't always be linear, and it's important not to be discouraged. "There are good days and bad days," says Bradt. "On your good days, don't try to conquer the world. But on your bad days, get out of bed and do what you promised yourself you would do that day."

Treating cancer fatigue with whole-person care.

Cancer fatigue can be complicated and multilayered, so working with a team who specializes in cancer rehabilitation and evaluates you as a whole person is important. "You have to have individualized holistic care which is going to incorporate your physical, psychological, social and spiritual well-being and help improve those areas," says Dr. Barksdale.

Integrative oncology — a whole-person approach to cancer care — combines conventional Western medicine with complementary therapies and can be used throughout treatment and into survivorship. This approach evaluates your individual needs, including health and personal factors that influence your well-being, while respecting your wishes and preferences for rehabilitation.

"We offer approaches like acupuncture, energy management, stress reduction, and other things we can do outside of our regular medical toolbox to help improve patient care," says Dr. Barksdale.

Learn more

Learn more about cancer fatigue and find a clinical trial at Mayo Clinic.

Mayo Clinic's Stephen and Barbara Slaggie Family Cancer Education Center offers free education and support to cancer patients, including online courses and a video library.

Join the Cancer: Managing Symptoms Support Group on Mayo Clinic Connect, an online community moderated by Mayo Clinic for patients and caregivers.

These online resources and articles are also available:

• Webinar: Thriving Beyond Cancer: Managing Cancer-Related Fatigue
• American Cancer Society: Cancer-Related Fatigue
• National Cancer Institute: Cancer Fatigue
• Mayo Clinic Minute: Coping with cancer-related fatigue