The exact causes of cancer-related fatigue and the best way to treat it are not always clear. Learn what doctors know about cancer-related fatigue and what you can do to handle it.
Fatigue, generally described as feeling tired, weak or exhausted, affects most people during cancer treatment. Cancer-related fatigue can be caused by treatment side effects or by the cancer itself.
Causes of cancer-related fatigue
Various factors can cause cancer fatigue, and the contributing factors in your case may be completely different from those of other people. However, possible contributing factors to this type of fatigue include:
Cancer
Cancer can cause changes in the body that may produce fatigue. For example, some types of cancer release proteins called cytokines that are believed to cause fatigue.
Other types of cancer may cause the body to need more energy, weaken muscles, cause damage to certain organs (such as the liver, kidneys, heart or lungs) or alter the body’s hormones, all of which can contribute to fatigue.
Cancer treatment
Chemotherapy, radiation therapy, surgery, bone marrow transplant and immunotherapy can cause fatigue. You may feel fatigue if cancer treatment damages healthy cells in addition to cancer cells. Or you may feel fatigue if your body is working to repair damage caused by treatment.
Some side effects of treatments (such as anaemia, nausea, vomiting, pain, insomnia and mood changes) also cause fatigue.
Anemia
You may have anemia if the treatment you’re receiving destroys too many healthy red blood cells. You may also have anemia if the cancer has spread to the bone marrow and interferes with red blood cell production or causes you to lose blood.
Pain
If you have chronic pain, you may be less active, eat less, sleep less and feel depressed; all of this can contribute to fatigue.
Emotions
Anxiety, stress or depression associated with a cancer diagnosis can also cause fatigue.
Lack of sleep
If you sleep less at night or wake up many times, you may feel fatigue.
Poor nutrition
To function well, the body must receive the energy provided by healthy eating. When you have cancer, your body may need more nutrients than normal. However, it can be difficult to get enough nutrients if treatment side effects, such as nausea and vomiting, make eating difficult.
Medications
Some medications, such as painkillers, cause fatigue.
Lack of exercise
If you’re used to leading a very active life, slowing down can cause fatigue.
Hormonal changes
Hormone therapy is a common cancer treatment that causes changes in the body’s hormone levels and can cause considerable fatigue. Hormonal changes can also occur as side effects of other cancer treatments.
Not everyone with cancer has fatigue. If you do have it, the degree of cancer fatigue can vary: from mild lack of energy to total debilitation.
Cancer fatigue may occur occasionally and be short-lived, or it may occur for several months after treatment has ended.
When to contact the doctor
It’s expected to feel some fatigue during cancer treatment. However, if you feel that cancer fatigue is persistent, lasts for weeks and interferes with your ability to carry on with your daily activities, tell your doctor.
What to tell the doctor
If you feel fatigued, the doctor may examine you and ask questions to assess the intensity and nature of the symptoms.
The doctor might ask you these questions:
- When did you start feeling fatigue?
- Has it progressed since diagnosis?
- How intense is it?
- How long does it last?
- What improves it?
- What makes it worse?
- How does it affect your daily life?
- Do you have shortness of breath or chest discomfort?
- Are you sleeping well?
- How and what are you eating?
- How do you feel emotionally?
The doctor will probably give you a physical examination and evaluate your medical history, the type or types of treatment you’re receiving or have received, and any medications you’re taking. The doctor may recommend tests, such as blood tests or x-rays, specific to your condition.
Coping strategies: medical treatments and self-care
Because cancer-related fatigue can be caused by many factors, the doctor may suggest more than one method to reduce and cope with symptoms. These may be self-care methods and, in certain cases, medications or medical procedures.
Self-care options
Coping with fatigue requires you to do some things. You could try the following:
- Take it easy. Set aside time during the day to rest. Take short naps (no more than an hour) during the day instead of resting for an extended period.
- Conserve energy. Save energy for the most important activities. Keep a record of the times when you feel better and do important activities during those times. Ask for help when you need it.
- Preserve your energy. Drinking plenty of fluids and eating well can keep your energy reserves high. If nausea and vomiting make eating difficult, talk to your doctor about these side effects.
- Move. Moderate exercise, such as brisk walking, cycling and swimming during the week can help you maintain your energy level. Exercise regularly when starting treatment. You’ll get used to the exercise routine, which may even help prevent fatigue during treatment. If you haven’t exercised much lately, check with your doctor before starting to make sure it’s safe. Then, start slowly and build up to at least 150 minutes of exercise a week, or half an hour of exercise five days a week. Try adding strength training, such as lifting weights, a few times a week.
- Consider integrative medicine options. Some people with cancer find relief from fatigue through meditation, yoga, and other mindfulness practices that promote relaxation. Massage and acupuncture can also be helpful. However, check with your doctor to make sure they’re safe, especially if your blood cell count is low or if you’re taking blood thinners.
- Consult with the doctor about supplements. Small studies have shown that supplements containing ginseng relieve fatigue. If you’re interested in trying supplements, talk to your doctor, as ginseng and other supplements may interfere with medications.
Don’t assume that the fatigue you’re experiencing is just part of having cancer. If it frustrates you or affects your ability to go about your day, it’s time to talk to your doctor.