Postmenopausal hot flushes: a disorder of thermoregulation.

The changes in cutaneous and body temperature and cutaneous conductance during hot flushes in eight postmenopausal women were studied. The vasomotor changes occurred approx. 45 sec after the patients experienced the initial subjective symptoms of the attacks. The rise in skin conductance appeared to be a more reliable index of the flushing episode than did the change in skin temperature. On the basis of the changes recorded it is suggested that the hot flush syndrome may represent a specific thermoregulatory disorder rather than being due to a non-specific central autonomic discharge. The episodes may be triggered by a neuroendocrine imbalance following the disruption of ovarian function and fall in estrogen production. In assessing the frequency and severity of hot flushes, and the effects of treatment, objective measurements of skin and core temperature and skin conductance should replace subjective criteria.