Cancer-related fatigue (CRF) is a persistent sense of tiredness/diminished energy related to cancer and/or its treatment, which is not relieved by rest, and which causes diminution in functional capacity and quality of life.
Additional proposed ICD-10 features that are not primarily consequences of depression include: diminished concentration, diminished motivation, insomnia or hypersomnia, nonrestorative sleep, short-term memory deficits, and marked emotional reactivity to fatigue.

CRF is often multifactorial, with biochemical, physiological, psychological, and behavioral dimensions that remain poorly defined.

Contributing factors may include:
- direct effect from cancer and/or cancer treatments
- sedating medications
- physical deconditioning
- psychiatric comorbidities (e.g., depression, anxiety)
- hypoxemia, severe anemia (Hb ≤8 g/dL), and possibly moderate anemia (Hb ≤11g/dL)
- systemic infection and/or or significant organ dysfunction (e.g., heart, liver, kidney, lung)
- electrolyte abnormalities (e.g., ↓Na+, ↓K+, ↓Mg++ , ↑Ca++)
- nutritional imbalance/impairment
- sleep disturbance
- uncontrolled pain

Specific treatments should be directed toward correcting identifiable causes, e.g., elimination of sedating drugs, correction of anemia or electrolyte imbalance.

Non-specific treatments may help reduce fatigue, optimize function, and promote adaptation.
1. Educate patient/family about CRF in order to promote adaptation/adjustment through setting realistic goals.
2. Aerobic exercise (20-30 minutes of [cumulative] exercise per day, at least 3 days per week) can improve cancer-related fatigue symptoms.
3. Drug therapy. The following drugs have been used with variable success:
- Psychostimulants. Methylphenidate: start with 2.5-5 mg and titrate as necessary to 15-30 mg O at 08:00 and noon. Modafanil: suggested initial dosing is 50 mg O qd and titrate as necessary to 200-400 mg O qd.
- Corticosteroids. Prednisone 7.5-10 mg O qd; dexamethasone 1-4 mg po qd; methylprednisolone 32 mg O qd.
- Megestrol acetate: 160 mg O three times a day
- Dietary supplements: ginseng, L-carnitine
4. Complementary therapies. Acupuncture may confer a potential benefit.

See reference for more information.

Adapted from Reinfield GM and Wilson GR. Palliative Care Network of Wisconsin. Fast facts and concepts #173. Cancer related fatigue. Internet. Accessed on January 25, 2016.