Physiological aspects of menopausal hot flush.

Eighteen hot flushes experimenced by eight menopausal women were studied and compared with the effects of warming in six premenopausal women. The hot flushes were associated with an acute rise in skin temperature, peripheral vasodilatation, a transient increase in heart rate, fluctuations in the electrocardiographic (ECG) baseline, and a pronounced decrease in skin resistence. Although premenopausal women had greater maximum increases in skin temperature and peripheral vasodilatation, they showed a much smaller decrease in skin resistance and no changes in heart rate or ECG baseline. These findings suggest that the onset of the hot flush is associated with a sudden and transient increase in sympathetic drive. Further investigations may lead to the development of a more specific alternative to oestrogen for relieving menopausal hot flushes.