You are here: 


Fatigue is a general lack of energy, tiredness or exhaustion. It is different from the tiredness a person usually feels at the end of the day. Fatigue is not necessarily related to activity and may not go away with additional rest or sleep. It is the most common symptom reported by people with cancer, especially during treatment. It may occur after chemotherapy, radiation therapy or stem cell transplant as the body uses energy to repair cells damaged by these treatments. Fatigue can greatly affect your day-to-day activities and quality of life.


Fatigue can be caused by cancer because some tumours compete with the body for nutrients. It can also be caused by cancer treatments, including surgery, chemotherapy, radiation therapy, biological therapy or stem cell transplant.

Fatigue can also be caused by other conditions related to cancer and its treatments, including:

  • fever
  • anemia
  • infection
  • lung, liver, heart or kidney problems
  • electrolyte imbalances
  • poor appetite
  • poor nutrition
  • dehydration
  • lack of exercise or mobility
  • sleep problems or disruption of normal sleeping habits
  • too much rest
  • pain
  • nausea and vomiting
  • drugs such as antinausea or pain-relieving medicines
  • stress
  • anxiety or depression

People with fatigue often have more than one of these factors. The exact reason why these factors cause fatigue in people with cancer is not known.


Symptoms of fatigue can vary depending on their cause and other factors. For example, it may be worse at the beginning and end of a chemotherapy treatment cycle. It can also increase throughout the course of radiation treatment.

Symptoms of fatigue include:

  • exhaustion, even after a good night’s sleep
  • lowered energy all of the time
  • trouble concentrating, remembering or thinking clearly
  • changes in emotions, including irritability or swings
  • general disinterest in life
  • tiring quickly during an activity
  • spending more time sleeping than usual
  • extreme paleness


Your doctor will try to find the cause of fatigue. This may include asking questions about the pattern of your fatigue and symptoms:

  • when fatigue started
  • how long fatigue has lasted
  • how severe fatigue is
  • what makes fatigue worse
  • what effect fatigue has on normal activities
  • sleep and rest habits or changes

Your doctor will also ask about medicines you take and treatments you’ve had. You may need to have the following tests:

  • physical and psychological exams
  • blood tests to check the levels of red blood cells, hemoglobin or iron

Managing fatigue

Fatigue can be acute, which means it is a short-term problem that goes away after treatment ends. It can also be chronic, which means it is a longer-lasting problem that continues long after you finish treatment. Follow-up after cancer treatment includes checking for fatigue.

Once the cause of fatigue is known, your healthcare team can suggest ways to treat it. Treatment may include nutritional supplements or medicines. If your red blood cell count is low, you may need a blood transfusion.

You can also try the following to help you cope with fatigue.

Get enough sleep

Try to get enough sleep during the night. Promote a good night’s sleep by playing relaxing music. You can also try drinking a glass of warm milk or having a warm bath or back rub before bedtime. Keep a regular sleep routine. Make sure your bed, pillows and sheets are comfortable.

Save and manage your energy

Use a journal to keep track of when your energy level is low and when it is high.

Save energy by doing activities for shorter periods. Plan rest periods before activities. Schedule short rest periods throughout the day or when you feel tired, but save the longest sleep for night. Too much rest can make you feel more tired.

Schedule appointments or activities for times when your energy level is high. Organize and prioritize activities. Do things that mean the most first and leave less important activities further down the list. Allow extra time for dressing and getting ready to go out so that there is no rush.

Ask about a flexible work schedule or reduced hours if you plan to work during treatment. Gradually resume a normal work schedule or duties as you feel up to it.

Keep in touch with friends and loved ones by phone or email if you don’t have the energy to meet them in person. Limit visitors and ask them to call before they visit. Take advantage of friends’ and relatives’ offers to help. Let them help prepare meals, do chores, drive or babysit.

Maintain good health

Ask your healthcare team to suggest exercises or activities you can do, such as walking.

Eat when you have the most energy. Try to have a nutritious snack every 2–3 hours during the day. Eat a well-balanced diet and drink plenty of fluids. Eat green leafy vegetables, liver and cooked red meats that are high in iron. Talk to a registered dietitian if necessary.

Take medicines as ordered by your healthcare team. They may prescribe iron pills to treat anemia. They may also give pain-relieving medicines if pain is a cause of fatigue. Psychostimulants can give a sense of well-being, decrease fatigue and increase appetite. They can also reverse the sedating effects of some drugs such as morphine. Antidepressants may be prescribed if depression is a cause of fatigue. Sleeping medicines may be needed to help improve sleep.


Lisa Hamel I’m living proof that one can lead a normal life after cancer.

Read Lisa's story

Cancer affects all Canadians

Icon - 1 in 2

Nearly 1 in 2 Canadians is expected to be diagnosed with cancer in their lifetime.

Learn more