”Tired,” “exhausted,” “weak,” “worn out,” “wiped out,” “no energy,” and “cannot concentrate” are all ways in which people with cancer have described the symptom of fatigue. Fatigue felt by people with cancer is different from fatigue felt occasionally by healthy individuals. Compared with “normal” fatigue, fatigue related to cancer treatment usually is more severe, lasts longer, and is unrelieved by sleep. For many people with cancer, fatigue is a more distressing symptom than pain and other symptoms because of how it can interfere with normal activities. Managing your fatigue is an essential part of your health care, and you should make sure to talk to your doctor or another member of your health care team about your fatigue.

Who is most likely affected?

It is important for people with cancer to know that feeling tired and weak is not necessarily a sign that the disease is getting worse. Fatigue can be caused by many factors, and the factors will differ among patients. Some of these factors are not related to treatment; for example, stress, other medical conditions, altered sleep/wake cycles, and reduced activity may contribute to fatigue.

Fatigue related specifically to cancer treatment can occur after all types of treatments, including surgery, chemotherapy, radiation therapy, hormone therapy, bone marrow transplantation, immunotherapy, and targeted biologic therapy. Treatment-related fatigue occurs primarily because the body needs extra energy to repair healthy tissue damaged by cancer treatment. Other treatment side effects may also cause fatigue; for example, pain, nausea and vomiting, and sleep disorders can all cause fatigue to occur or to become more severe.

Physical and mental fatigue may be a side effect of medications you take for pain or other symptoms, especially the following types of drugs:

Strong pain relievers
Sleeping medications
Antidepressants
Antinausea medicine
Antiseizure drugs

Sometimes the interaction of two or more medications may cause fatigue. The more medications you take, the more likely it is that an interaction may cause fatigue. Another cause of fatigue is anemia, a condition in which the level of red blood cells is low.

Why does this occur?

Fatigue occurs in almost all people during cancer treatment, regardless of the type of cancer or the type of treatment. How fatigue affects people with cancer depends on the age of the person, his or her general health, the types of treatment they receive, and the normal level of activity before treatment.

When does this occur?

When fatigue occurs depends on the type of treatment. Many people feel tired after surgery as their body heals. The after-effects of anesthesia, the use of strong pain relievers, and limitations on activity can make you feel tired and weak for a few days to a few weeks after surgery.

If you are receiving chemotherapy, you will probably feel the most tired about 2 hours after treatment. Over the course of chemotherapy, fatigue typically peaks within a few days after the beginning of treatment and then gradually gets better until the next treatment cycle begins. Radiation therapy takes longer to produce fatigue; a feeling of being tired and weak usually starts a few weeks after treatment begins and gradually diminishes after treatment ends.

Fatigue may be fairly constant or may occur from time to time. Some people feel less tired once treatment has been completed and others may feel tired for several months after treatment has ended. Long-term fatigue (1 year or more) is most common among people who have received bone marrow transplantation and high-dose chemotherapy.

How can this be managed?

Your doctor may ask you to rate your feeling of fatigue on a scale of 1 to 10 or ask you to describe it as mild, moderate, or severe. Your doctor may also ask how your fatigue affects your daily activities. These questions will help your doctor determine whether there is a specific cause for your fatigue. If so, he or she will prescribe treatment for the cause. For example, if your red blood count is low, your doctor may prescribe a drug to help increase the growth of new red blood cells. Be sure to tell your doctor about all the medications you’re taking, including those prescribed by your primary doctor and any over-the-counter drugs, vitamins, or herbal supplements you take. You may need to stop taking some drugs or supplements or change drugs to avoid interactions that cause fatigue.

Most people think more rest will help relieve fatigue. However, the opposite is true. Increasing activity and performing regular exercise are actually the best ways to help manage and reduce symptoms of fatigue. Studies have found that some people with cancer decreased their level of fatigue by half when they performed regular aerobic exercise, such as walking or bike riding. You should try to start exercising early during treatment, as it may feel too difficult to start once peak fatigue occurs. Make sure you check with your doctor before you start a regular exercise program.

Saving your energy is another way to relieve fatigue. Decide what tasks or activities are important to you and focus on doing them when you feel best during the day. Accept the fact that you cannot do everything, and ask family and friends to help you with specific tasks.

Regular rest is important also. You should set aside time in your day to rest or take a nap. If you are working, try to rest or nap during part of your lunch or break time. Several short periods of rest are more beneficial than one long rest. If you nap too much during the day, you won’t sleep as well at night.

There are many other ways you can help yourself feel less tired including following a structured daily routine, balancing activity and rest, engaging in activities to “distract” or relax you, maintaining proper nutrition, and seeking relief of other symptoms. If you are working during your treatment, talk to your supervisor before treatment begins about the possibility of fatigue and ways you can handle it; such as taking time off and scheduling treatments to avoid the need to work on important tasks when fatigue may be at its peak.

If your fatigue is severe, your doctor or nurse may recommend that you take a stimulant medicine for a short period of time.

Ways to Manage Fatigue Related to Cancer Treatment

Conserve energy	Set priorities for activities and do only what is most important Schedule important activities for times of the day when you have the most energy Ask friends and family to help Sit down when washing or grooming Use assistive devices if necessary (canes, walker, etc.)
Balance activity and rest	Follow a structured daily routine Pace yourself — attend to one activity at a time and space activities throughout the day Participate in regular physical activity, such as walking or bike riding Take frequent rest periods or naps, but limit each nap to 45 minutes Get 8 hours of sleep each night
Engage in activities that provide relaxation or distraction from fatigue	Perform deep breathing exercises Use imagery techniques Read Listen to music Pray/meditate Play games
Seek relief of other symptoms	Talk to your doctor about managing symptoms that may contribute to fatigue such as pain, nausea and vomiting, and depression
Maintain adequate nutrition	Eat a well-balanced diet to help promote healing

When should I talk to my doctor?

You should describe your level of fatigue to your doctor at every office visit. You should also call your doctor’s office immediately if you have the sudden onset of any of the following symptoms:

Confusion
Dizziness
Loss of balance
Too tired to get out of bed for more than 24 hours
Fatigue that has gotten worse or sudden decrease in energy level
Feeling of breathlessness (out of breath) or of a racing heart after mild activity

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