Why Stress Makes You Sweat

Sweat is an all too familiar result from stress, and researchers have been diving deeper into the reasons for this. Scientists believe stress-sweat has an evolutionary role in sending warning signals to those around us. The brain reacts negatively to a stranger's body odor; meanwhile, the scent of a family member can be calming to somebody under stress, according to a new study. Sweat caused by being over-heated is produced by eccrine glands which are located all over the body, just under the skin. Stress, anxiety, fear, and sexual arousal cause sweat produced by apocrine glands, found only in certain areas, such as under the arms. Bacteria and fatty substances are found in this sweat, and they cause body odor, whereas heat-sweat consists only of water and salt. Stress-sweat is activated by the same hormones, mostly adrenaline, that draw us to react quickly when faced with an overwhelming situation. "It's highly tied to the fight or flight response," says George Preti, a faculty member at Monell Center. Still, the reason for sweating while under stress is still not quite understood.

The Wall Street Journal, 2/4/2013