TENS machines are generally used to reduce the severe pain you have in some of your body parts. Initially these machines were only used in hospitals as they were expensive but due to the goodness and wellness provided by these machines they are now even being purchased for household. These machines lead to wellness by sending electrical signals through your body to relieve the pain.
Pain is a part and parcel of life. Whenever your body has some issues it indicates the symptoms by sending pain signals to the brain and thus we experience it. We have to live with the fact that our body at some part of the time becomes weak and signals us that we need a proper treatment. When there is some injury to your body, the nerve receptors below the skin send electric signals to the brain. One method of easing your pain is to provide your nervous system with high speed "good feelings" such as rubbing your injured area.