The role of endocrine systems in chronic pain mechanisms is slowly getting increasing experimental and clinical consideration. Many painful conditions appear to be directly and/or indirectly induced, reduced or, in some cases, modulated by hormones. We have done much work in trying to understand the relationship between hormones and pain, with particular attention to the hypothalamus-pituitary-gonadal axis. To expand our knowledge of this field, we have directed our attention to another axis, the hypothalamus-pituitary-thyroid (HPT). The literature on thyroid functions is vast but very few studies have focused on the HPT axis and pain. The few available data are considered in the present review to stimulate interest in the possible interactions between the HPT axis and pain.