What can cause cancer-related fatigue?
There is rarely one explanation. Possible contributors include:
- the cancer itself;
- chemotherapy, radiotherapy, immunotherapy, hormone treatment or surgery;
- anaemia or infection;
- pain, nausea or other symptoms;
- reduced food or fluid intake;
- poor sleep;
- medicines that cause drowsiness;
- anxiety, low mood or the mental effort of living with uncertainty;
- loss of strength and fitness after a period of reduced activity;
- another medical condition, such as a thyroid problem.
Several of these may occur together. That is why a substantial or changing level of fatigue deserves assessment rather than an assumption that nothing can be done.
Tell the team what fatigue is stopping you from doing
“I feel tired” can mean many things. It helps to describe the effect on daily life. For example:
- Are you able to wash and dress without resting?
- Can you prepare food or leave the house?
- Is concentration affecting work, reading or driving?
- Is the fatigue constant, or does it follow treatment on particular days?
- Are breathlessness, dizziness, pain, fever or weight loss present as well?
Your team may review symptoms, medicines, blood tests, sleep and emotional wellbeing. The answer is not always another test, but this information helps decide what needs checking.
Rest and activity both have a place
Rest is part of recovery. Trying to push through severe fatigue can leave you needing longer to recover afterwards.
At the same time, spending most of the day inactive can reduce strength and make activity feel harder. For many people, a small and gradually adjusted amount of movement is more helpful than alternating between doing everything on a good day and being exhausted afterwards.
The appropriate level depends on your symptoms and treatment. Exercise during cancer treatment and getting outside during treatment give more detail about adapting activity and when to ask first.
Pacing daily tasks
Pacing means using available energy deliberately rather than waiting until it is exhausted. You might:
- identify the tasks that matter most that day;
- break a larger task into shorter stages;
- sit for activities that do not require standing;
- plan demanding tasks for the time of day when energy is usually better;
- accept practical help with shopping, transport or meals;
- include something enjoyable, not only essential chores.
This is not giving in to fatigue. It is a way of protecting energy while recovery and treatment continue.
When to seek prompt advice
Contact your team promptly for fever, new or worsening breathlessness, chest pain, fainting, confusion, bleeding, inability to drink, or another symptom they have told you to report urgently.
A sudden change is different from a familiar pattern after treatment. If fatigue is affecting safety, personal care or the ability to eat and drink, tell the team rather than waiting for the next routine appointment.
Tell your team what fatigue is preventing you from doing, and whether its pattern has changed. That helps them assess possible causes and the support you need.
