The present invention provides a treatment device for applying electrical impulses to a living body through the skin, for treating a variety of clinical conditions. The device comprises a pair of electrodes for contact with the skin, and a waveform generator for repeatedly generating an AC waveform for applying electrical impulses through the electrodes to the skin. A detector detects changes in the skin impedance and generates detector output signals representing the skin impedance. Means responsive to the detector output signals for monitor the responsivity of the skin, and indicator means activated by the monitoring means generate a first indication when a predetermined level of responsivity is reached and a second indication when a pre-determined treatment has been administered.