In this paper, Dr. Bo Wikland of Stockholm, Sweden proposes two valuable hypotheses. The first is that most hypothyroid patients must suppress their TSH levels to recover from their symptoms and have a good quality of life. My own clinical experience, as well as his, and my clinical trials fail to refute this hypothesis. In the vernacular of medical research, this means these experiences strongly support his first hypothesis.

Dr. Wikland's second hypothesis proposes why most hypothyroid patients must suppress their TSH levels with thyroid hormone for therapeutic success: first, autoimmune thyroiditis is the most common cause of hypothyroidism; second, the TSH triggers and maintains autoimmune activity; and third, consequently, a low TSH is a prerequisite to patients reducing or stopping altogether the pathological activity in the thyroid gland.

The research literature has long shown that TSH suppression is necessary if patients with partial peripheral resistance to thyroid hormone are to recover their health. However, like Dr. Wikland, other clinicians and I have long observed that most hypothyroid patients, too, must suppress their TSH levels if they are to recover from their symptoms.

Medical hypotheses that are not falsified by our current bank of knowledge warrant being  subjected to rigorous experimental testing. The reason is, if we find that the hypotheses are true (that is, if testing fails to refute them), clinicians can use the information to further the health and well-being of the patients we are here to serve.

Dr. Wikland's hypotheses are not falsified by our current knowledge, making it highly likely that they are true. Because of this, in view of the widespread dissatisfaction with the conventional approach to diagnosing and treating hypothyroid patients, I believe experimental testing of his hypotheses is imperative. I firmly believe such testing will fail to refute his hypotheses. If I am right, the new paradigm of the diagnosis of hypothyroidism—which he called for in a recent editorial in Thyroid Science—will have a sound scientific foundation. From that foundation, the paradigm should, in the interest of hypothyroid patients' health, begin to rise and revise the current conventional practice of the diagnosis and treatment of hypothyroidism.

We thank Dr. Bo Wikland and his colleagues for contributing to the advancement of clinical thyroidology, and Dr. Wikland for his valued contributions to Thyroid Science.

Key Words. Autoimmune thyroid disease • B12 deficiency • Clinical symptoms • Criterion of optimal treatment • Fine-needle aspiration • Free T4 • Hypothyroidism • Quality of life • Subclinical hypothyroidism • Thyroid antibodies • TSH