Cancer-related fatigue is one of the most common symptoms experienced during and after cancer treatment. It is defined as a persistent sense of physical, emotional or mental exhaustion that is disproportionate to the level of activity performed and is not fully relieved by rest or sleep.

Fatigue can affect a person's ability to carry out daily activities, work, concentrate, maintain social relationships or enjoy leisure activities. Some people describe it as exhaustion, lack of energy, weakness or difficulty thinking clearly.

Fatigue may occur:

  • At the time of cancer diagnosis.
  • During chemotherapy, radiotherapy, surgery, hormone therapy, immunotherapy or targeted therapies.
  • After treatment has ended, sometimes persisting for months or even years.

What Can Cause Fatigue?

Cancer-related fatigue often has multiple causes. Common contributing factors include:

  • The cancer itself.
  • Cancer treatments.
  • Anaemia.
  • Poorly controlled pain.
  • Sleep disturbances.
  • Anxiety, stress or depression.
  • Physical inactivity and loss of muscle mass.
  • Malnutrition or weight loss.
  • Infections.
  • Hormonal or metabolic abnormalities.
  • Other symptoms such as breathlessness, nausea or diarrhoea.

For this reason, it is important to inform your healthcare team if fatigue develops or becomes worse.

Assessment of Fatigue

Your doctor or nurse may ask:

  • When the fatigue began.
  • How much it affects your daily activities.
  • How well you are sleeping.
  • What medications you are taking.
  • Whether you have associated symptoms such as pain, low mood or breathlessness.

Keeping a diary may be helpful to record:

  • Your energy levels throughout the day.
  • The activities you perform.
  • The times when you feel better or worse.
  • Your sleeping and resting patterns.

Exercise Is the Most Effective Intervention

Physical exercise is one of the most effective strategies for reducing cancer-related fatigue.

Recommended Activities

  • Walking.
  • Indoor or outdoor cycling.
  • Swimming.
  • Adapted strength-training exercises.
  • Yoga.
  • Tai Chi.
  • Qigong.

Recommendations

  • Start gradually.
  • Adapt the intensity to your abilities.
  • Try to remain active on most days of the week.
  • Avoid spending long periods in bed or sitting down whenever possible.

Look After Your Sleep

Good-quality sleep can help manage fatigue.

Tips for Better Sleep

  • Maintain regular times for going to bed and waking up.
  • Limit long daytime naps.
  • Keep your bedroom dark, quiet and comfortable.
  • Avoid using screens before bedtime.
  • Reduce caffeine intake during the afternoon and evening.
  • Engage in regular physical activity during the day.

If sleep problems persist, discuss them with your healthcare team.

Nutrition and Hydration

A healthy diet helps maintain energy levels.

Recommendations include:

  • Eating regular meals.
  • Prioritising protein-rich foods.
  • Maintaining adequate hydration.
  • Avoiding skipping meals.
  • Consulting a registered dietitian if you are losing weight or having difficulty eating.

Managing Stress and Emotional Wellbeing

Anxiety, worry and depression can increase feelings of exhaustion.

Interventions with the strongest evidence include:

  • Cognitive Behavioural Therapy (CBT).
  • Mindfulness-based programmes.
  • Fatigue management education.
  • Relaxation techniques.

These approaches may be helpful both during treatment and after treatment has finished.

Organising Daily Activities

Planning ahead can help conserve energy.

Useful Strategies

  • Prioritise the activities that matter most.
  • Break large tasks into smaller, more manageable steps.
  • Alternate periods of activity and rest.
  • Take advantage of times of the day when your energy levels are highest.
  • Ask for help when needed.
  • Use assistive devices or equipment if they make tasks easier.

At Home

The following suggestions may help:

  • Prepare larger quantities of food and freeze portions for later use.
  • Use home grocery delivery services when available.
  • Sit down for some household activities.
  • Delegate physically demanding tasks whenever possible.

Treating Reversible Causes

Before considering specific treatments for fatigue, your healthcare team will assess whether there are underlying factors that can be treated, such as:

  • Anaemia.
  • Infections.
  • Pain.
  • Sleep disorders.
  • Depression or anxiety.
  • Hormonal abnormalities.
  • Malnutrition.

Addressing these problems can significantly improve fatigue.

Family Members and Carers

Carers and family members can help by:

  • Understanding that fatigue is a real and common symptom.
  • Accompanying the patient to medical appointments.
  • Helping to organise activities and rest periods.
  • Assisting with household tasks.
  • Encouraging safe and appropriate physical activity.

When Should You Seek Medical Advice?

Contact your healthcare team if:

  • Your fatigue becomes significantly worse.
  • It prevents you from carrying out basic daily activities.
  • It is accompanied by dizziness, breathlessness or palpitations.
  • You have significant difficulty sleeping.
  • You experience symptoms of anxiety or depression.
  • You have weight loss or a marked reduction in appetite.