Sweating during night sleep.

The mode of sweating during night sleep was investigated with a polygraphical method, in special reference to changes of its rate in association with EEG pattern. The results were compared with those made in daytime sleep.While in general the rate of thermogenic sweating was closely associated with EEG depth of sleep in daytime sleep, association between the two phenomena was not so close in night sleep, especially in later sleep cycles. Night sleep was also characterized by a downward overall trend of sweat rate. Those significant differences in the mode of thermogenic sweating between daytime and nocturnal sleep could in part be attributed to diurnal variations of body temperature, but appear to depend more definitely upon differences in the character of sleep. However, the latter per se may be caused by the mechanisms controlling the diurnal body rhythm.Our observations reveal also that, although in general psychogenic sweating was absent during sleep, it could appear during paradoxical sleep in association with dreams accompanied by emotional excitement, and also as a manifestation of arousal response during sleep