A CBC, TSH, 25 hydroxyvitamin D and ferritin are essential for all women with hair loss
The other tests that are needed depend on your history of hair loss
- All premenopausal women with "regular" periods and no acne or hair growth on the face really don't need an extended panel of tests. It's a waste for most to order every hormone possible.
- Women with irregular periods need blood work on day 3 of the menstrual cycle for LH, FSH, androstenedione, DHEAS, sex hormone binding globulin, prolactin, free and total tesosterone and AM cortisol
- Women with hair loss and severe acne or hair growth on the face require free and total tesosterone, DHEAS and androstenedione
- Women with poor bowel absorption or restrictive diets need serum zinc levels
- Women with sun sensitivity, joint pains, mouth or vaginal ulcers, cough, or anemias benefit from ANA and ESR. I add ENA (extractable nuclear antigen) if dry eyes, dry mouth or concerns for autoimmunity are present.
In short, there are four tests that are key: CBC, TSH, ferritin and vitamin D. The other tests to order depend on the patient's history. I don't order the same blood tests on all patients. It depends on their story.