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

Initial Workup for Fatigue in Female Patients

The initial workup for a female patient presenting with fatigue should begin with screening for fatigue severity using a 0-10 numeric rating scale or categorization as none, mild, moderate, or severe, followed by appropriate laboratory testing including complete blood count, comprehensive metabolic panel, thyroid function tests, and assessment of treatable contributing factors. 1, 2

Fatigue Severity Assessment

• Screen all patients for fatigue severity using either a 0-10 numeric rating scale or categorization as none, mild, moderate, or severe 2
• Patients with scores of 0-3 (mild fatigue) require no further assessment; rescreening at regular intervals is sufficient 2
• Patients with scores of 4-10 (moderate to severe fatigue) warrant a more focused evaluation 2
• Patients with scores ≥7 typically experience a marked decrease in physical functioning and require prompt intervention 2

Focused History and Physical Examination for Moderate to Severe Fatigue

• Conduct a thorough review of systems to identify affected organ systems and guide further workup 3
• Perform an in-depth fatigue assessment including onset, pattern, duration, changes over time, and associated or alleviating factors 3
• Evaluate interference with normal functioning and daily activities 3
• Document the presence of B symptoms (fever, drenching night sweats, unexplained weight loss >10% of total body weight over 6 months) 1
• Assess for other associated symptoms such as cough, dyspnea, and lymphadenopathy 1

Laboratory Studies

• Complete blood count with differential to evaluate for anemia, infection, or hematologic malignancies 1
• Comprehensive metabolic panel including liver enzymes, alkaline phosphatase, and albumin 1
• Thyroid-stimulating hormone (TSH) and free thyroxine (fT4) to rule out hypothyroidism, which commonly presents with fatigue 1, 4
• Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) to evaluate for inflammation 1
• Consider HIV testing and tuberculosis screening (IGRA or TST) if risk factors are present 1

Assessment of Treatable Contributing Factors

• Pain should be assessed and treated effectively as it commonly clusters with fatigue 2
• Screen for emotional distress, depression, and anxiety, which frequently co-occur with fatigue 2
• Evaluate sleep disturbance for sleep quality, quantity, and hygiene 2
• Review medication side effects as potential contributors to fatigue 2
• Screen for alcohol/substance use that may contribute to fatigue 2

Imaging Studies

• Consider chest X-ray as initial screening for pulmonary pathology if respiratory symptoms are present 1
• Consider contrast-enhanced CT scan of neck, chest, and abdomen if lymphadenopathy, organomegaly, or malignancy is suspected 1

Special Considerations for Hypothyroidism

• Hypothyroidism is a common cause of fatigue in women and should be considered in all cases of unexplained fatigue 4
• Anemia is present in 20-60% of patients with hypothyroidism and may be the first sign of the disease 5
• Physical examination alone cannot reliably diagnose or exclude hypothyroidism (positive likelihood ratios range from 1.0 to 3.88) 6
• TSH is the single best screening test for primary thyroid dysfunction 7

Common Pitfalls to Avoid

• Relying solely on physical examination to diagnose conditions like hypothyroidism, as this has poor diagnostic accuracy 6
• Overlooking medication side effects as potential contributors to fatigue 2
• Failing to recognize that fatigue rarely occurs in isolation and often clusters with other symptoms 2
• Neglecting to screen for emotional and psychological factors that may contribute to fatigue 2
• Assuming mild to moderate fatigue requires extensive workup when it may only need monitoring and reassessment 3