The hands, feet, armpits (axilla), and the groin area are the most active regions of perspiration because of the relatively high concentration of sweat glands in these areas. (sciencedaily.com)
The body loses moisture through perspiration as well as through respiration (think of your breath fogging a window). (scientificamerican.com)
In addition to mood swings and menstruation, changes in hormones result in an increase in perspiration. (verywellfamily.com)