Fatigue is a feeling of being physically, emotionally, or mentally tired, weak, or exhausted. It is a symptom of cancer itself and also the most common side effect of cancer treatment. It does not mean the cancer is getting worse or that the cancer treatment isn't working. Some people with cancer have described fatigue as being tired to the bones or hitting a wall. Others say it is the most distressing side effect of cancer treatment. Fatigue may cause decreased ability to work or do physical activity. It also makes it hard to be involved with family, socialize with friends, or complete daily activities. Sometimes it even causes people to miss cancer treatments. It can also affect concentration or attention.
Fatigue can come and go or stay constant for awhile. Fatigue from chemotherapy tends to happen a few days after the treatment, peaks, and then gets better before the next treatment. Fatigue from radiation may not happen right away. It can develop over the first 2 to 3 weeks of treatment and increase as the treatment continues. It may last 3 months or more after the treatment is finished. Attentional fatigue can last up until 2 or 3 years after treatment is completed. Fatigue is different for everyone, so it is important that the person who is experiencing it describes how he or she feels.
Some of the causes of fatigue are understood, but not all of them. Fatigue may be related to physical changes caused by cancer itself or its treatment (chemotherapy, biotherapy, radiotherapy, or surgery). The fatigue people have when receiving cancer treatment tends to be more severe than for healthy people. This fatigue lasts longer and is not relieved by sleep. Certain things can make the fatigue worse. For example, if the person with cancer has pain all the time, or pain that is not controlled, then this can cause irritability, prevent sleep, and make the person feel tired. Lack of sleep may also cause irritability. If the person with cancer feels short of breath much of the time, he or she may feel anxious or tired from the work of breathing. Depression, nausea and vomiting, or diarrhea can worsen fatigue. Most of these problems can be relieved to lessen fatigue.
Other things that can worsen fatigue may be harder to treat, like financial worries and fears or concerns related to the cancer or its treatment. It is important to talk about these, and there are members of the healthcare team who can help, like the social worker or counselor. Talking about fears or problems can make a person feel more in control and able to find solutions to the problems. Often, a support group is very helpful to provide ongoing support and also as a forum to share creative solutions to problems with fatigue. Talk to your healthcare provider for more information.
Anemia (reduced red blood cells) is related to fatigue. Chemotherapy can reduce the number of oxygen-carrying red blood cells, so the body does not get as much oxygen as it needs. Healthcare providers may prescribe a blood transfusion or a medicine to boost the body's ability to produce red blood cells. Talk to your healthcare provider about the risks and benefits in your specific case.
People who are not well-nourished, who don't drink enough fluid and are dehydrated, or who are not able to move around much tend to have fatigue more easily. The way a person handles stress, thinks, or behaves can influence fatigue. It is important that a person with cancer learn ways to conserve energy. Energy is like money, and people have only a limited amount of it. Think carefully about how to spend it. What activities are most important? What activities help restore energy? These are the activities that people with cancer should spend their energy on.
The American Cancer Society recommends asking your healthcare provider the following questions about cancer treatment and fatigue:
Will the cancer therapy I am receiving cause fatigue?
How severe will my fatigue be?
Are there effective treatments to control my fatigue or make it better?
How will you decide which treatment I will receive?
What can be done if the treatment does not make my fatigue better?
What are the likely side effects of the proposed treatments?
What other healthcare professionals can help manage my fatigue?
Is my fatigue caused by anemia? If so, how will it be treated?
To manage related fatigue or to lessen it, a person on chemotherapy can also:
Eat a well-balanced diet and talk to your healthcare provider about taking a multivitamin daily.
Drink plenty of fluids.
Regularly do gentle exercise.
Talk about problems with friends and family or the healthcare team.
Ask for help with chores or tasks.
Be sure to talk with your healthcare provider about how you can manage or lessen fatigue.