Laboratory Workup for Hair Loss, Peeling Nails, and Fatigue
Order ferritin, vitamin D, zinc levels, complete blood count (CBC), and comprehensive metabolic panel (CMP) as your initial laboratory evaluation for this presentation. 1
Essential First-Line Tests
Iron Studies
- Check serum ferritin as the priority test - this is the most sensitive marker for iron deficiency, which commonly causes telogen effluvium and diffuse hair loss even before anemia develops 1
- Ferritin levels below 40-50 ng/mL are associated with hair loss, even when hemoglobin remains normal 1
- Add CBC to assess for anemia, which would explain the fatigue and can cause both hair and nail changes 1
Nutritional Deficiencies
- Vitamin D level - deficiency is associated with hair follicle cycling abnormalities, hair loss, and fatigue 1
- Zinc level - deficiency causes telogen effluvium, impaired hair growth, and nail dystrophies including peeling 1
- These nutritional deficiencies are frequently overlooked but easily correctable causes of this symptom triad 1
Thyroid Verification (Critical Step)
Even if thyroid function was previously reported as "normal," you must verify what was actually tested 1:
- Confirm both TSH and free T4 were measured - TSH alone may miss subclinical thyroid dysfunction that causes hair loss and fatigue 1
- Add anti-TPO antibodies - positive antibodies indicate Hashimoto's thyroiditis, which can cause hair loss, nail changes, and fatigue even when TSH and T4 are within normal range 1
Additional Metabolic Screening
- Comprehensive metabolic panel (CMP) - screens for liver dysfunction, kidney disease, electrolyte abnormalities, and glucose abnormalities that can cause this symptom complex 2
- Consider fasting glucose or HbA1c if diabetes risk factors are present, as uncontrolled diabetes causes hair loss, nail changes, and fatigue 2
Special Consideration for Postmenopausal Women
If the patient is postmenopausal, the above workup remains the same priority, but consider:
- Free and total testosterone, DHEA-S - only if there are additional signs of androgen excess such as hirsutism or androgenetic alopecia pattern 3
- Routine endocrinologic evaluation is not recommended for the majority of patients unless additional hyperandrogenism signs are present 3
Common Pitfalls to Avoid
- Do not assume "normal thyroid" means thyroid is irrelevant - verify that both TSH and free T4 were checked, not just TSH alone, and add anti-TPO antibodies 1
- Do not overlook nutritional deficiencies - ferritin, vitamin D, and zinc are frequently deficient in patients with this presentation and are easily correctable 1
- Do not order extensive hormonal panels routinely - endocrinologic testing beyond thyroid is only warranted when clinical features suggest hyperandrogenism 3