Treatment Side Effects - Fatigue
Reviewed by: HU Medical Review Board | Last reviewed: April 2022 | Last updated: May 2022
Fatigue is a persistent feeling of exhaustion or lack of energy that does not improve with sleep. A common side effect of treatment for breast cancer, fatigue frequently occurs in combination with depression, pain, or difficulty sleeping, which can worsen the effect of fatigue. Fatigue can cause a significant negative impact on a person’s quality of life, potentially disrupting their ability to work, engage in social activities, and affecting their personal relationships. Some research has found that fatigue has a more substantial negative impact on cancer patient quality of life in comparison to all other cancer-related symptoms.1,2
Causes of fatigue in metastatic breast cancer
Fatigue can be a symptom of breast cancer itself, and many women complain of fatigue before they are diagnosed with breast cancer. Studies have found that women diagnosed with breast cancer frequently have fatigue before they begin treatment. Women who have fatigue, poor sleep, and/or depression before treatment starts are more likely to experience fatigue and a poor quality of life during treatment with chemotherapy as compared to women who experience less symptoms prior to treatment.2
Many treatments used for breast cancer also can cause fatigue, including chemotherapy, radiation therapy, immunotherapy and targeted therapy.2,3 Those receiving chemotherapy are more likely to experience fatigue, with an estimated 80% to 96% of patients receiving chemotherapy experiencing fatigue. The fatigue experienced during treatment can persist even after treatment is finished. Among breast cancer survivors, approximately 30% of patients experience moderate to severe fatigue after they finish their initial course of treatment, and fatigue among breast cancer survivors can persist in some patients for up to ten years after they have been diagnosed.2
Sleep disturbances can also add to fatigue. Many treatments for breast cancer can disrupt sleep, including those which can cause night sweats and hot flashes. In breast cancer survivors, hot flashes are experienced by approximately 40-70% of patients and have been linked with increased disturbances of sleep.2
The impact of fatigue on quality of life
Fatigue can impact every area of a person’s life, making every day activities more challenging. A person experiencing fatigue may find it difficult or impossible to engage in daily activities, social events, or physical activity. Their relationships may suffer as they have less energy to spend time with family and friends. Fatigue can also cause difficulties with focusing, concentrating, or remembering. In certain cases, fatigue can be the result of mood changes, including depression.1
Depression and fatigue
One of the common symptoms of depression is fatigue, and fatigue may also increase a person’s risk of developing depression. It can be difficult to determine which came first in some people but treating depression can have a benefit on a person’s fatigue. Likewise, treating fatigue can potentially improve a person’s mood.1,2
Anemia and fatigue
Chemotherapy can decrease the number of healthy blood cells. A decrease in the number of red blood cells, known as anemia, can also cause fatigue. Treating anemia with medications, blood transfusions, or diet changes may help decrease fatigue.1
Pain and fatigue
Pain can also increase fatigue. Advanced breast cancer can cause pain, and the treatment options for advanced breast cancer may also cause pain as a side effect. If pain is worsening a person’s fatigue, pain medication may need to be adjusted. However, in some cases, too much pain medication can worsen fatigue.1 It’s important for the individual to discuss with their doctor how pain, and the medications used to treat it, are affecting them.
Ways to manage fatigue
The first approach to treating fatigue is to treat any underlying causes, such as anemia, pain, or depression. Treating symptoms such as pain, depression, and managing other side effects of chemotherapy like nausea and vomiting can often have a beneficial effect on fatigue. In addition, replenishing nutritional deficiencies, which may occur as a result of nausea and vomiting, can be helpful in reducing fatigue.4
While fatigue can impact a person’s ability to engage in physical activity, exercise has been shown to help reduce the severity of fatigue. Physical activity can also potentially improve emotional well-being and overall quality of life in people with breast cancer. One study found that enjoyable physical activity lessened fatigue and pain in breast cancer survivors.1 Talk to your doctor before beginning a new exercise program, or if you have questions on how best to modify your existing routines.
Some medications are being studied for their ability to treat fatigue in cancer patients, including certain antidepressants and anti-inflammatory drugs.1Complementary therapies may also be beneficial in reducing fatigue, including meditation, yoga, acupuncture, tai chi, and qi gong.1,4 It is important that patients tell their doctors about any complementary practices they are considering taking part in to ensure that nothing interferes negatively with their treatment; however, many of these approaches can often be used along with traditional therapies.