From the Guidelines
Laboratory tests used to evaluate fatigue include a complete blood cell count with differential, comprehensive metabolic panel, and endocrinologic evaluation, such as 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 determine the most appropriate laboratory tests.
- A complete blood cell count (CBC) with differential can help identify anemia, infections, or other blood disorders that may be contributing to fatigue.
- A comprehensive metabolic panel (CMP) can assess electrolytes, hepatic, and renal function, which can be affected in various conditions that cause fatigue.
- Endocrinologic evaluation, including TSH levels, can help identify thyroid disorders, which are a common cause of fatigue. These tests can help healthcare providers narrow down potential underlying causes of fatigue and develop an effective treatment plan. It is crucial to note that the choice of laboratory tests may vary depending on the patient's specific symptoms, medical history, and physical examination findings, as emphasized in the guidelines 1. In clinical practice, a thorough evaluation, including laboratory tests and physical examination, is necessary to determine the underlying cause of fatigue and provide appropriate management.
From the Research
Laboratory Tests for Evaluating Fatigue
The following laboratory tests are used to evaluate fatigue:
- Complete Blood Count (CBC) 2, 3, 4, 5
- Hemoglobin levels 6
- Red blood cell (RBC) indices 4
- White blood cell (WBC) count with differential 4
- Electrolytes and urea tests 5
- Pulmonary function tests 5
Specific Components of CBC
The following components of CBC are useful in evaluating fatigue:
- White blood cell (WBC) count 3
- Neutrophil-to-lymphocyte ratio (NLR) 3
- Hemoglobin (Hb) 3
- Mean corpuscular volume (MCV) 3
- Red cell distribution width (RDW) 3
- Platelet count 3
- Mean platelet volume (MPV) 3
- Platelet-to-lymphocyte ratio (PLR) 3
Clinical Context
These laboratory tests are used in various clinical contexts, including: