Sympathetic Skin Testing


Typically, a pair of electrodes 1 cm apart is applied to the thighs, hand, or foot.  A stimulus is then applied such as a loud noise, electric shock, or cough, this then typically leading to a brief change in sweating and therefore electrical conductivity.  In conditions with marked loss of sweating the response may be lost, but beyond this the method is not very useful because of the extreme variability in the response, both between patients and when testing the individual on repeated occasions. It is thus not useful for quantification of degree of sweating.