Is TENS therapy the same thing as electrotherapy? This is a question that we get asked often. In simplest terms, yes it is but keep in mind that electrotherapy can encompass many types of therapy while TENS therapy is just simply pain relief.
For example, cranial electrotherapy stimulation or CES is a type of electrotherapy that works by stimulating the brain to balance levels of serotonin and melatonin while reducing cortisol levels. While EMS or electric muscle stimulation centers more on developing muscles.
As for needing both TENS therapy and CES or cranial electrotherapy stimulation, that answer is typically no. At least not in the same device. The major reason for this is that CES therapy really only requires two pairs of electrodes to be clipped to your ears. While TENS therapy usually requires pain relief for a larger area: the back, shoulders, knees are examples of this. You want to place four pads on these areas to make sure that the entire area is being treated, two electrodes typically cannot do that.
If you need both TENS and CES, we usually advise purchasing two separate devices. EMS/TENS devices are very similar though, those can certainly be purchased as an "all in one" so you have the benefit of both muscle development, pain relief and massage in one device.