Apparatus for transcutaneous nerve stimulation in humans, the apparatus comprising: a housing; stimulation means mounted within the housing for electrically stimulating nerves; an electrode array releasably mounted to the housing and connectable to the stimulation means, the electrode array comprising a plurality of electrodes for electrical stimulation of nerves; control means mounted to the housing and electrically connected to the stimulation means for controlling at least one characteristic of the stimulation means; user interface means mounted to the housing and electrically connected to the control means for controlling the stimulation means; and a strap attached to the housing; wherein the strap is configured to hold the housing, stimulation means and electrode array at a specific anatomical location to treat pain; characterized in that the control means is configured to determine a therapeutic stimulation intensity for electrically stimulating nerves, wherein the control means is adapted such that the therapeutic stimulation intensity is determined by: causing the stimulation means to apply transcutaneous electrical nerve stimulation to a patient at a first stimulation intensity; causing the stimulation means to automatically increase the stimulation intensity from said first stimulation intensity until an electrotactile sensation threshold is identified by a user using the user interface means; and calculating the therapeutic stimulation intensity from said electrotactile sensation threshold by automatically adding a pre-determined intensity offset to the stimulation intensity associated with said electrotactile sensation threshold. a housing; stimulation means mounted within the housing for electrically stimulating nerves; an electrode array releasably mounted to the housing and connectable to the stimulation means, the electrode array comprising a plurality of electrodes for electrical stimulation of nerves; control means mounted to the housing and electrically connected to the stimulation means for controlling at least one characteristic of the stimulation means; user interface means mounted to the housing and electrically connected to the control means for controlling the stimulation means; and a strap attached to the housing; wherein the strap is configured to hold the housing, stimulation means and electrode array at a specific anatomical location to treat pain; characterized in that the control means is configured to determine a therapeutic stimulation intensity for electrically stimulating nerves, wherein the control means is adapted such that the therapeutic stimulation intensity is determined by: causing the stimulation means to apply transcutaneous electrical nerve stimulation to a patient at a first stimulation intensity; causing the stimulation means to automatically increase the stimulation intensity from said first stimulation intensity until an electrotactile sensation threshold is identified by a user using the user interface means; and calculating the therapeutic stimulation intensity from said electrotactile sensation threshold by automatically adding a pre-determined intensity offset to the stimulation intensity associated with said electrotactile sensation threshold. causing the stimulation means to apply transcutaneous electrical nerve stimulation to a patient at a first stimulation intensity; causing the stimulation means to automatically increase the stimulation intensity from said first stimulation intensity until an electrotactile sensation threshold is identified by a user using the user interface means; and calculating the therapeutic stimulation intensity from said electrotactile sensation threshold by automatically adding a pre-determined intensity offset to the stimulation intensity associated with said electrotactile sensation threshold.