Autoimmune thyroiditis and chronic fatigue connection:
This research article that was reprinted on an MD's website, was originally published by the Townsend Letter For Doctors and Patients.
In this study, not only were patients with chronic fatigue found to have autoimmune thyroiditis as the cause of it, but they were suffering this hypothyroid symptom of severe fatigue, despite having normal TSH levels.
The article also points out the importance of FNA biopsy to diagnose chronic lymphocytic thyroiditis, due to antibodies tests alone, sometimes failing to identify it.
"Fine-needle aspiration cytology of the thyroid gland was performed on 219 patients complaining of fatigue of more than one year’s duration. Eighty-seven patients (40%) were found to have definite histological evidence of chronic lymphocytic (autoimmune) thyroiditis.
Most doctors will rule out a diagnosis of hypothyroidism if the TSH level is normal. The results of this study, however, suggest that chronic autoimmune thyroiditis is associated with clinical hypothyroidism, even in the presence of normal TSH values."