The proper treatment for decreased thyroid system function in any given patient certainly depends on the underlying cause. As discussed previously, there are several causes of DTSF, low body temperature patterns, and the symptoms of MED, and more than one cause can be present at the same time. DTSF can be caused by a hypothalamic problem, hypopituitarism, hypothyroidism, and Wilson’s Temperature Syndrome.

Hypopituitarism and hypothyroidism both result in deficient production of T4, which is the raw material the body uses to produce the active thyroid hormone T3. In such cases the treatment of choice is T4 because of its long half-life (which helps provide steady T3 levels), once-a-day administration, and usefulness in the treatment of such cases. Patients with hypopituitarism and hypothyroidism may, however, suffer with Wilson’s Temperature Syndrome at the same time. In such cases, T4 therapy may not be adequate because impaired conversion of the T4 supplementation to the active compound T3 may prevent sufficient normalization of body temperature patterns, and, in some cases, can even feed the vicious cycle of Wilson’s Temperature Syndrome.