Feeling weakness or fatigue is common in people with cancer, but it's different for each person. Feeling weak is often one part of having fatigue. It's important to remember that fatigue might get better after treatment ends for some, but last many months to years after treatment for others.
Weakness is decreased strength. If this is caused by surgery in a certain part of the body or loss of a body part, the weakness might be helped by physical therapy or occupational therapy. If weakness is caused by having an infection or having changes in blood levels, such as low blood counts, low electrolytes, or changes in hormones, treatment to help with the specific problem can help decrease weakness.
Fatigue can have many causes. People with cancer describe fatigue in many ways. They may say they feel tired, weak, exhausted, weary, worn-out, or slow. They may say they have no energy and can’t concentrate. They also talk about having heavy arms and legs, little drive to do anything, being unable to sleep or sleeping too much. They may feel moody, sad, irritable, or frustrated.
No lab tests or x-rays can diagnose or show your level of fatigue. The best measure of fatigue comes from the way you describe your fatigue level to your cancer care team. You can describe your level of fatigue as none, mild, moderate, or severe. Or you can use a scale of 0 to 10, where 0 means no fatigue at all, and 10 means the worst fatigue you can imagine. Ask your doctor or nurse how to describe your fatigue so they can understand how it affects your everyday life.
If you have moderate (4 to 6 on the 0 to 10 scale) to severe (7 to 10 on the 0 to 10 scale) fatigue, your doctor could ask you for more information. You might be asked questions like:
Some signs of fatigue or weakness often look a lot like those of depression, and it’s easy to confuse the two. Depression involves an inability to feel pleasure – people who are depressed feel sad or unworthy. They may give up hope. You can have fatigue and not be depressed, although some people have both fatigue and depression.
Sometimes it may be hard to find a label for what you’re feeling. Your doctor might want you to see a mental health professional to get another opinion on whether depression is part of the problem. If it is, treatment can help.
Because the symptoms of fatigue in people with cancer are usually caused by more than one problem, doctors, nurses, social workers, physical therapists, pharmacists, dietitians and nutritionists, and a number of others might be involved in treating your fatigue or weakness. These symptoms often are caused by more than one problem.
Treating different specific cancer-related problems, like anemia or pain, might make you feel better, but other things may need to be done, too. For this reason your cancer care team might have you try many different things to help manage your fatigue or work with a palliative care team to address multiple symptoms.
There’s no way to know if you'll have fatigue, how bad it will be, or how long it will last. In some cases, it can be hard for the doctor to figure out exactly what’s causing your fatigue. Still, there are things you can do to help manage it.
Exercise, yoga, massage therapy, counseling, and dietary or nutritional counseling are all used to help treat fatigue and weakness.
If you’re having problems sleeping or sleeping too much, your doctor or nurse may suggest sleep therapy. This therapy can help you minimize sleep disturbances and learn improved sleep hygiene.
More research is needed and is being done in this area, but there are stimulant drugs your health care team may prescribe you if your fatigue doesn't improve. These stimulants are only prescribed for a short period. It's important you talk to your doctor about the benefits of taking these drugs, as well as the different side effects that may occur such as daytime sleepiness, withdrawal symptoms, insomnia, memory problems, or allergic reactions.
Research studies have shown that physical activity during and after cancer treatment can decrease fatigue. Your health care team can refer you to exercise specialists (physical therapist, physical medicine, rehabilitation specialist) to help you with a safe exercise plan that can be modified to your condition. Yoga has helped improve sleep for some people with different types of cancer who are going through treatment.
Talk to your doctor first and always be careful about exercising if you have any of these conditions because they can lead to injury, pain, bleeding, or other problems if they aren’t taken into account before you start to exercise:
Massage therapy has helped some patients during cancer treatment by possibly reducing stress levels and improving sleep. Talk to your doctor first before starting massage therapy.
Behavioral therapy or mindfulness-based stress reduction has helped cancer survivors reduce fatigue. Sharing your feelings with others can help ease the burden of fatigue. You can also learn coping hints from others by talking about your situation. Ask your health care team to put you in touch with a support group. Or contact us to find a group near you.
Mental health counseling, stress management training, and relaxation exercises are some ways you can learn to improve the feelings related to fatigue and help overcome the tiredness you feel.
Studies have shown some breast cancer survivors reported lower distress and fatigue with counseling and behavioral therapy.
Nutritional deficits can add to the problems of fatigue and weakness. Your health care team may refer you to a dietitian to check your calorie and nutritional intake. You may be prescribed vitamins or supplemental electrolytes (sodium, potassium, calcium, iron, or magnesium) to help reduce your symptoms. Cancer patients, who may be managing other side effects (nausea, vomiting, bowel problems, mouth sores ) or different medical conditions that affect eating, can benefit from this counseling.
These may be signs of other problems that need to be treated.
The American Cancer Society medical and editorial content team
Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.
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Last Revised: February 1, 2020
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