What is the appropriate laboratory workup for a patient presenting with fatigue?

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Last updated: May 21, 2025View editorial policy

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From the Guidelines

A fatigue lab workup should begin with a complete blood count (CBC) with differential, a comprehensive metabolic panel, and an endocrinologic evaluation, including thyroid-stimulating hormone (TSH) levels, as recommended by the American Society of Clinical Oncology 1. When evaluating fatigue, it is essential to consider the presence of other symptoms, onset, and severity of fatigue to guide the laboratory evaluation.

  • The CBC with differential helps assess for anemia, compares end-of-treatment hemoglobin/hematocrit with current values, and evaluates other cell lines (WBC and platelets) 1.
  • The comprehensive metabolic panel assesses electrolytes, hepatic, and renal function, providing valuable information on the patient's overall metabolic status 1.
  • The endocrinologic evaluation, including TSH levels, helps rule out thyroid disorders, which are common causes of fatigue 1. Additional tests, such as vitamin levels (B12, folate, vitamin D), iron studies (ferritin, iron, TIBC), and a urinalysis, may be considered based on the patient's history, physical examination findings, and associated symptoms 1. It is crucial to tailor the workup based on the patient's individual needs, as fatigue is often multifactorial, and addressing several contributing factors simultaneously may be necessary to improve outcomes and quality of life 1.

From the Research

Fatigue Lab Workup

There are no research papers to assist in answering this question, as the provided study 2 is related to cyclic AMP phosphodiesterase activity in Morris hepatomas and does not provide information on fatigue lab workup.

  • The study 2 discusses the fractionation of rat liver cAMP phosphodiesterase into four peaks of activity using isoelectrofocusing column chromatography.
  • It examines the changes in phosphodiesterase activity in relation to the growth rate of Morris hepatomas.
  • However, it does not provide any information on the laboratory workup for fatigue.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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