What is the initial workup for a patient presenting with fatigue?

Initial Workup for Fatigue

The initial workup for fatigue should begin with screening using a 0-10 numeric rating scale or categorization as none, mild, moderate, or severe, followed by a focused history, physical examination, and targeted laboratory testing for patients with moderate to severe fatigue (scores ≥4). 1

Screening and Assessment

• All patients presenting with fatigue should be screened using a 0-10 numeric rating scale (0 = no fatigue; 10 = worst fatigue imaginable) or categorized as none, mild, moderate, or severe 1
• Mild fatigue (scores 0-3) requires only education and periodic rescreening 2
• Moderate to severe fatigue (scores 4-10) warrants a more comprehensive evaluation 2, 1
• Patients with scores ≥7 typically experience significant functional impairment 2

Focused History

• Assess onset, pattern, duration, and changes over time of fatigue 1
• Evaluate for associated symptoms that may suggest specific organ system involvement 2, 1
• Document interference with normal functioning and daily activities 2
• Review all current medications, including over-the-counter drugs and supplements 2
• Screen for emotional distress, including depression and anxiety 1
• Assess sleep quality, quantity, and hygiene 1
• Evaluate alcohol/substance use patterns 1
• Determine the presence of pain, which commonly clusters with fatigue 1

Physical Examination

• Conduct a thorough physical examination focused on identifying potential causes of fatigue 2
• Pay particular attention to vital signs, lymphadenopathy, cardiopulmonary status, abdominal examination, and neurological assessment 2
• Look for signs of anemia (pallor), thyroid dysfunction, or other systemic diseases 3

Laboratory Testing

• Initial laboratory testing should be targeted rather than extensive, as studies affect management in only 5% of patients 3
• Basic laboratory workup should include:
  • Complete blood count (CBC) to assess for anemia 3
  • Basic metabolic panel to evaluate kidney function and electrolytes 4
  • Thyroid-stimulating hormone (TSH) to screen for thyroid dysfunction 3
  • Inflammatory markers (ESR or CRP) if inflammatory conditions are suspected 4
• If initial results are normal, repeat testing is generally not indicated unless new symptoms develop 3

Special Considerations

• Consider more extensive workup when fatigue is accompanied by unintentional weight loss, pain, pulmonary complaints, or other concerning symptoms 2
• Be aware that fatigue rarely occurs in isolation and often clusters with other symptoms 1
• The most common causes of persistent fatigue include sleep disorders, depression (18.5%), and excessive psychosocial stress 4
• Previously undiagnosed cancer is a rare cause of fatigue (0.6%) but should be considered in patients with risk factors or concerning symptoms 4

Management Approach

• Develop a structured plan for regular physical activity including stretching and aerobic exercise, such as walking 3
• Address any identified contributing factors (pain, sleep disturbance, medication side effects) 1
• Schedule regular follow-up visits rather than sporadic urgent appointments for effective long-term management 3
• Consider cognitive behavioral therapy for patients with chronic fatigue 3
• For patients with depression, selective serotonin reuptake inhibitors may improve energy levels 3

Common Pitfalls to Avoid

• Conducting excessive laboratory testing when initial results are normal 3
• Overlooking medication side effects as potential contributors to fatigue 1
• Failing to consider psychiatric causes such as depression and anxiety 4
• Focusing exclusively on somatic causes, which can lead to overdiagnosis 4
• Neglecting to provide education about fatigue management strategies 5