PE may be associated with hypothyroidism and may contribute to reduction in thyroid hormone output. Many women in our database have hypothyroidism. They are prescribed high to very high levels of thyroid hormone replacement therapy (e.g., 0.1 mg Synthroid) and still report not feeling “normal.” The PE was reduced (e.g., very low-dose tricyclic, antidepressant, or carvedilol) and after a series of thyroid hormone blood tests, Synthroid levels were reduced (to as low as 0.01 mg) or, in a few cases, even eliminated, and follow-up thyroid panels (blood tests) are normal. There are also women, in whom normalizing P&S imbalance does not relieve the hypothyroidism, suggesting that for these patients, the endocrine dysfunction does not have an autonomic component. The process almost always involved documenting and treating the PE, the patient reporting hyperthyroid symptoms, documenting hyperthyroidism via blood test panel, reducing hormone replacement therapy, the patient reporting PE symptoms, titrating PE therapy, the patient reporting hyperthyroid symptoms, and so on for (typically) two or three cycles. This process seems to be due to the differing time frames between autonomic and hormone system responses and adaptation. The clinical finding that PE may be involved in hypothyroidism (i.e., the PSNS may downregulate thyroid function) also helps to differentiate and document autonomic from endocrine processes and enables the physician to be more aggressive with the primary disease.