This study reviewed the efficacy of a foot bath using lavender oil. The subjects were eight males, so that the confounding effect of the autonomic imbalance associated with the menstrual cycle was eliminated. The observation items were the HF component of HRV (a parasympathetic nervous activity index) / skin surface temperature / skin depth temperature / blood pressure, and subjective evaluation. We compared the effects of a foot bath in water containing lavender oil (experimental group) and a foot bath in water not containing lavender oil (a control group), and measured by measuring the above parameters from 15 minutes before the foot bath, until 30 minutes after a foot bath (the foot bath itself lasted for 10 minutes) .
Increase of the superior extremity skin temperature after a foot bath during a foot bath significantly in an experimental group in several minutes was noted during and for several minutes after the foot bath. Furthermore, the increase of the superior extremity skin temperature was maintained for longer in comparison with that in the control group. On the other hand, the blood pressure decreased significantly in the experimental group for rest about 25-30 minutes. The HF component of HRV increased significantly in the experimental group at 20 minutes. Therefore, our results suggested that a foot bath in water containing lavender oil enhanced parasympathetic nervous activity.