Reviewed: Annie Angle, cancer nurse (Dip. Oncology Nursing, Royal Marsden, London)
Fatigue is a feeling of severe tiredness experienced by many people who have cancer and its treatment (chemotherapy, radiotherapy, hormone therapy and, sometimes, surgery). Cancer fatigue is very different from everyday tiredness.
It can happen suddenly. Unlike everyday tiredness, it is not necessarily brought on by exercise or a long day's activity. Resting does not always help relieve the fatigue. It can go on for weeks, months or even years after you finish treatment. Doctors call this ‘chronic fatigue' - long-lasting tiredness.
Most people will regain their normal energy levels between six months and a year after their treatment ends. For some people it can take longer. Fatigue can be overwhelming and frustrating. It can touch many parts of your life.
Different people have different symptoms. People with cancer fatigue describe feeling weak, exhausted, sleepy, drowsy, weary, confused or impatient. Some describe it as a ‘whole body experience' and say they ‘just cannot move'. Others have tired or sore limbs and feel breathless, even after only a little activity.
For many people, cancer fatigue is unlike anything they have experienced. It can often be difficult to describe and hard for others to understand.
Many people with cancer say fatigue is the most difficult of all side effects from their cancer and its treatment. Fatigue can affect how you think as well as how you feel.
Some people can even get depressed. If you have continued feelings of sadness, have trouble getting up in the morning or don't feel like doing things that you used to enjoy, talk to your doctor. You may have depression, and counselling or medication may help you.
‘I had no idea that I would still be feeling tired five months after finishing treatment ... I didn't know how to make it better and I was scared that's how it would be: that I wouldn't go back to normal, that I would never go back to having energy again.' (Georgina)
Fatigue during treatment can be caused by the side effects from cancer treatments such as:
A common side effect from some of these treatments is having too few red blood cells (anaemia). Anaemia means there are fewer red blood cells to carry oxygen through your body.
The cancer itself can also cause fatigue. Some cancer tumours produce toxins. These can cause tiredness or stop cells making important minerals in our body, such as potassium and calcium. When our levels of such minerals get too low it affects our muscles and may cause weakness and tiredness.
Cancer treatment can sometimes affect hormone levels, which can also reduce energy levels. Other things related to your illness can make you feel tired: not eating well, pain, not sleeping well, feeling stressed, having depression, coping with infections, some drugs, and not exercising.
You may also be affected by other health problems; side effects from pain-relieving drugs, steroids, sleeping tablets or antidepressants; and emotional problems. Doctors are still trying to find out the exact causes and ways of managing fatigue after treatment finishes.
Friends and family may advise you to ‘take it easy' and ‘get plenty of rest'. But staying in bed for a long time can cause you to feel even more tired. If you rest for a long time, your muscles will weaken and you will find it harder to be active when you want to. So being as active as you can, without making the fatigue worse, is your best approach.
Talk to your doctor or nurse about how much bed rest and exercise they would recommend. Other people may not understand that rest does not make your fatigue go away. It may help to explain to them that fatigue is different from normal tiredness.
Speak to your doctor before starting an exercise program. Discuss other ways of managing the fatigue and living as normal a life as possible. Tell your doctor or nurse if:
You may find that the fatigue begins to lift when your cancer treatment ends. However, some people are fatigued for some time after treatment ends. Sometimes the fatigue will lift, then return again. You may need to be patient if your recovery isn't as fast as you'd like.
If your fatigue is worrying you, talk to your doctor or nurse. They may be able to estimate how long the fatigue could last. Contact the Cancer Council Helpline on 13 11 20 (cost of a local call). This is a confidential service staffed by cancer nurses. Information is available in languages other than English.