Cancer-related fatigue

Overview

Cancer-related fatigue (CRF) is a persistent, distressing sense of physical, emotional, or cognitive exhaustion that is related to cancer or its treatment. Unlike normal fatigue, CRF is not relieved by rest or sleep and significantly interferes with daily activities and quality of life. It is one of the most common and debilitating symptoms experienced by individuals with cancer, affecting patients during and after treatment. CRF can continue for months or even years after cancer therapy has ended, making it a chronic concern for many survivors.

Causes

The exact cause of cancer-related fatigue is multifactorial and often varies from person to person. Contributing factors include:

• Cancer itself: Tumors can produce substances that disrupt normal metabolism and energy regulation.

• Cancer treatments:

  • Chemotherapy and radiation therapy – damage healthy cells and tissues, leading to fatigue.

  • Surgery and immunotherapy – can also cause physical stress and energy depletion.

• Anemia: Common during cancer and treatment, reducing oxygen delivery to tissues.

• Poor nutrition: Appetite loss, nausea, or treatment side effects can lead to inadequate calorie and protein intake.

• Insomnia, pain, or anxiety disrupt sleep quality.

• Psychological factors: Depression, anxiety, and emotional distress amplify feelings of fatigue.

• Medications: Drugs such as painkillers, anti-nausea medications, and sedatives may contribute to fatigue.

• Hormonal changes: Cancer treatments can affect thyroid function or sex hormone levels, leading to low energy.

Symptoms

Cancer-related fatigue manifests in multiple ways and can affect physical, mental, and emotional health. Common symptoms include:

• Persistent tiredness not relieved by rest or sleep

• Feeling physically weak or sluggish

• Difficulty concentrating or thinking clearly (mental fog)

• Loss of motivation or interest in activities

• Low mood, irritability, or frustration

• Increased need to rest, even after minor tasks

• Sleep disturbances, including insomnia or excessive sleepiness

• Shortness of breath with minimal exertion

Diagnosis

There is no specific test to diagnose cancer-related fatigue. Diagnosis is based on clinical evaluation and exclusion of other potential causes. The diagnostic process includes:

• Detailed symptom history: Including onset, duration, severity, and impact on daily life.

• Physical examination: To check for signs of anemia, infections, or other medical issues.

• Blood tests: To assess for anemia, thyroid disorders, nutritional deficiencies, or organ dysfunction.

• Fatigue scales and questionnaires: Tools such as the Brief Fatigue Inventory (BFI) help quantify fatigue severity and monitor progress.

• Psychological assessment: Screening for depression or anxiety, which may mimic or worsen fatigue.

Treatment

Effective treatment of cancer-related fatigue requires a holistic, individualized approach that addresses both physical and psychological contributors. Common treatment strategies include:

• Physical activity: Light to moderate exercise (e.g., walking, yoga) has been shown to reduce fatigue and improve energy levels.

• Cognitive-behavioral therapy (CBT): Helps manage negative thoughts and promotes healthy coping strategies.

• Sleep management: Sleep hygiene techniques and addressing sleep disorders can significantly improve fatigue.

• Nutritional support: Ensuring adequate protein, calories, and hydration to support recovery and energy.

• Medication management:

  • Treating anemia or hypothyroidism if present.

  • Adjusting medications that may contribute to fatigue.

• Mind-body practices: Meditation, mindfulness, and relaxation techniques can reduce stress and enhance energy.

• Energy conservation techniques: Learning to pace activities, prioritize tasks, and take rest breaks.

Prognosis

The prognosis for cancer-related fatigue depends on the underlying cause, cancer type, and treatment phase. For many patients, fatigue improves gradually after treatment ends. However, in some cancer survivors, it may persist for months or years and require ongoing management. With appropriate interventions, most individuals can achieve a meaningful reduction in fatigue and an improved quality of life. Early recognition and a proactive, multidisciplinary approach are key to successful fatigue management in cancer patients and survivors.