Fatigue & Chronic Fatigue Syndrome

Key Features

Essentials of Diagnosis

• Inquire about

  • Weight loss

  • Fever

  • Sleep-disordered breathing

  • Medications; substance use

General Considerations

• Clinically relevant fatigue is composed of three major components

  • Generalized weakness (difficulty in initiating activities)

  • Easy fatigability (difficulty in completing activities)

  • Mental fatigue (difficulty with concentration and memory)

• Fatigue is often attributable to

  • Overexertion

  • Poor physical conditioning

  • Sleep disturbance

  • Obesity

  • Undernutrition

  • Emotional problems

• One study found that atopy (especially numerous atopic syndromes) is associated with chronic fatigue syndrome

• The lifetime prevalence of significant fatigue (present for at least 2 weeks) is about 25%

• Neuropsychological and neuroendocrine studies reveal abnormalities in most patients but no consistent patterns

Clinical Findings

Symptoms and Signs

• Screen for psychiatric disorders

• Evaluation and classification of unexplained chronic fatigue involves

  • History and physical examination

  • Mental status examination (abnormalities require appropriate psychiatric, psychological, or neurologic examination)

  • Screening laboratory tests (see below)

• Fatigue is classified as chronic fatigue syndrome if criteria for severity of fatigue are met and four or more of the following symptoms are concurrently present for 6 months or longer

  • Impaired memory or concentration

  • Sore throat

  • Tender cervical or axillary lymph nodes

  • Muscle pain

  • Multijoint pain

  • New headaches

  • Unrefreshing sleep

  • Postexertion malaise

• Fatigue is classified as idiopathic chronic fatigue if criteria for fatigue severity or the above symptoms are not met

Differential Diagnosis

• Hyperthyroidism and hypothyroidism

• Heart failure (HF)

• Infection (eg, endocarditis, tuberculosis, hepatitis, Lyme disease, HIV, mononucleosis)

• Chronic obstructive pulmonary disease (COPD)

• Interstitial lung disease

• End-stage kidney disease

• Sleep apnea

• Anemia

• Autoimmune disease

• Multiple sclerosis

• Irritable bowel syndrome

• Parkinson disease, multiple sclerosis

• Cerebral vascular accident

• Cancer

• Medications (eg, β-blockers, sedatives)

Diagnosis

Laboratory Tests

• Obtain

  • Complete blood count

  • Erythrocyte sedimentation rate

  • Serum electrolytes

  • Serum glucose

  • Kidney function and serum electrolytes

  • Liver biochemical tests

  • Thyroid function tests

  • Antinuclear antibody

  • Urinalysis

  • Tuberculin skin test

• Consider, as indicated

  • Serum cortisol

  • Rheumatoid factor

  • Immunoglobulin levels

  • Lyme serology in endemic areas

  • HIV antibody test

Treatment

Medications

• Treat affective or anxiety disorder only if present

• Treat postural hypotension with fludrocortisone, 0.1 mg orally daily, and increased dietary sodium

• Psychostimulants, such as methylphenidate

  • Have shown inconsistent results in treatment of cancer-related fatigue

  • Have shown improvement in mental fatigue and cognitive function in those with traumatic brain injury

• Vitamin D replacement in those deficient or with kidney transplant

Therapeutic Procedures

• Resistance training and aerobic exercise lessens fatigue in a number of chronic conditions, including

  • HF

  • COPD

  • Arthritis

  • Cancer

• Treatment of chronic fatigue syndrome involves a comprehensive multidisciplinary intervention

  • Optimal medical management of coexisting ...