This Study intends to study the pain relief potential of transcutaneous electrical nerve stimulation (TENS) machines in people suffering from kidney stones.

The trial will be conducted in the Emergency department at the Angliss Hospital. The patients will be unaware of which arm of the trial they are in. The TENS machine will be applied by a consultant emergency physician with at greater 7 years’ experience In the active arm (Group B -which will be the even numbers in the randomization sequence)) there will be placement of 4 electrodes (2 in parallel) over the topical site of the affected kidney ( Lt or Rt flank - over L1 to L4 area), and the output TENS will be increased until the patient feels muscle contraction (this will be individualised to each patient- the usual range of TENS is 15 to 35mA) and then reduce the output until the patient feels comfortable. This will be individualised to each patient to ensure each patient receives the optimal therapy from the TENS machine. The placement and the dosage of the TENS machine including the incremental increase of voltage will be done by specialist emergency physicians who are at least 7 years in experience). The duration of the active arm will be for exactly 60 mins with a timer present on the TENS machine and the machine will automatically switch off at the 60 minute mark. The TENS therapy will be administered only once in a single session. Strategies used to monitor adherence includes direct supervision as this trial will be conducted in a Emergency ward or Emergency Department. Furthermore since the placement of the pads is on the back of the patient there is limited ability of the patient to to remove pads without assistance. The TENS machine is set up at the start of the trial and once activated is locked , thereby making it difficult to be tampered with. There will be 15 minutely checks on the patient for the duration of the hour to ensure that the patient is still experiencing the sensation from the TENS machine.