From the Research
Laboratory Tests for Fatigue
The recommended blood test panel for a young, healthy patient presenting with fatigue is not well-established, as the evidence suggests that laboratory tests have limited utility in diagnosing the cause of fatigue.
- According to 1, laboratory studies affect management in only 5 percent of patients, and if initial results are normal, repeat testing is generally not indicated.
- A study published in 2 found that while certain laboratory tests, such as circulating immune complexes and atypical lymphocytosis, were more common in patients with chronic fatigue syndrome, these tests lacked sufficient sensitivity to be diagnostic.
- Another study 3 found that the presence of an abnormal laboratory result in a fatigued individual does not necessarily indicate the cause of fatigue, and that psychological causes should be considered.
Specific Laboratory Tests
Some studies have investigated the usefulness of specific laboratory tests in evaluating fatigue.
- A study published in 4 found that certain laboratory markers, such as ACTH levels, estradiol levels, and relative neutrophil count, may be useful in supporting the diagnosis of post-infectious chronic fatigue syndrome in adolescents.
- However, it is essential to note that these findings may not be generalizable to all patients presenting with fatigue, and that the utility of these tests in diagnosing the cause of fatigue is still uncertain.
Clinical Guidelines
Clinical guidelines do not recommend routine blood tests for young, healthy, asymptomatic patients, as they have no proven value in early detection of diseases and may even be harmful 5.
- The evaluation of patients with fatigue should focus on identifying common secondary causes, such as lifestyle issues, physical conditions, mental disorders, and treatment side effects, rather than relying solely on laboratory tests 1.