A portable, battery powered apparatus (10) generates an electrical signal between electrodes (15a, 15b) to be applied to the skin of a patient for reduction or prevention of snoring or obstructive sleep apnoea. The signal comprises electrical stimulation at a frequency of 1 - 100Hz and the signal comprises a stimulation free period of at least 0.5 seconds every 20 seconds, avoiding muscle fatigue when used for long periods, e.g. overnight.
