Fatigue

Differentials

• Psychological Causes

  • Stress, burnout, major depression, anxiety disorders

  • Chronic fatigue syndrome (CFS) if fatigue persists >6 months with other features (unrefreshing sleep, post-exertional malaise)

• Sleep-Related

  • Sleep deprivation (shift work, insomnia, poor sleep hygiene)

  • Obstructive sleep apnoea (OSA) → snoring, witnessed apnoeas, daytime somnolence

• Infectious

  • Viral/post-viral illness (EBV, CMV, influenza, COVID-19)

  • Chronic infections (hepatitis B/C, HIV) less common but possible

• Haematological

  • Anaemia (iron deficiency from menorrhagia or GI bleeding, B12/folate deficiency)

  • Haemolytic anaemias, though rarer, can also cause chronic fatigue

• Substance-Related

  • Excess alcohol or illicit drug use

  • Medication side effects (e.g. beta-blockers, sedatives, analgesics)

• Endocrine/Metabolic

  • Hypothyroidism (common cause in mid-older adults, especially females)

  • Diabetes mellitus (poor glycaemic control)

  • Addison’s disease (adrenal insufficiency; consider hyperpigmentation, hypotension)

• Cardiorespiratory

  • Arrhythmias, heart failure, COPD, CKD

  • Check for SOB, orthopnoea, chest pain or peripheral oedema

• Malignancy

  • Lymphoma, leukaemia, multiple myeloma (look for weight loss, night sweats, bone pain)

• Gastrointestinal

  • Coeliac disease (malabsorption → iron deficiency)

  • Chronic liver disease

Red Flags

• Acute onset in an older patient who was previously well

• Weight loss, lymphadenopathy, fever (suggestive of malignancy or chronic infection)

• SOB, palpitations (possible cardiac or respiratory disease)

• Neurological symptoms (e.g. weakness, functional decline)

• Severe functional decline or inability to perform daily tasks

History

• Acute vs Chronic Onset: Chronic is more common, but acute or subacute changes prompt urgent investigation.

• Impact on Function: Work, social, academic performance.

• Support System: Evaluate for burnout if caring for others or high job stress.

• Sleep Patterns: Quality, duration, any daytime somnolence or snoring (OSA?).

• Caffeine Intake: Excess consumption can disrupt sleep.

• Medication Review: Look for side effects (sedation, hypotension).

• Substance Use: Alcohol, drugs.

• Associated Symptoms: E.g. menorrhagia or GI blood loss (possible anaemia), polyuria/polydipsia (diabetes), weight change (thyroid disorder).

Investigations

• Initial Bloods:

  • FBC (rule out anaemia)

  • Fasting BGL or HbA1c (diabetes check)

  • UEC (renal function)

  • LFTs

  • ESR/CRP (inflammatory markers)

  • Iron studies (ferritin, transferrin saturation)

  • TFTs (thyroid function)

• Further Tests (case-dependent):

  • B12, folate (if macrocytosis or dietary risk)

  • Coeliac serology (if GI symptoms or iron deficiency anaemia)

  • HIV or hepatitis serology (risk factors)

  • Sleep study (suspected OSA)

  • ECG if palpitations or arrhythmias suspected

Management

No Red Flags

• Reassurance & Lifestyle Advice: Many cases are short-lived or mild.

• Avoid Alcohol/Smoking: If relevant to patient’s fatigue.

• Education: Emphasise self-limiting nature in post-viral or benign causes.

• Regular Sleep Schedule: Maintain good sleep hygiene.

• Relaxation Techniques: CBT-based strategies, mindfulness, meditation, yoga, guided breathing.

• Physical Activity:

  • 150 mins/week low-impact aerobic exercise (walking, cycling), improving energy levels.

  • Encourage a balanced pace—gradual increments if unfit.

• Nutritional Review:

  • Balanced diet, adequate protein and micronutrients.

  • Maintain healthy BMI (<25).

• Follow-up:

  • Review in 4 weeks to assess progress, recheck for red flags.

  • If persistent without improvement, reconsider investigations (e.g. for CFS, malignancy, organ dysfunction).

Notes

• In older adults, new-onset fatigue may mask serious illness (e.g. malignancy, heart failure).

• Address psychosocial stressors (work overload, financial, relationship issues).

• If suspect Chronic Fatigue Syndrome (CFS), see specific guidelines (≥6 months duration, post-exertional malaise, rule out other causes).