effective in painful menstruation] One study encouraged providers to try the TENS unit with patients, on the grounds that they found it to be " non-invasive , efficient, and easy to use". [http://www.ncbi.nlm.nih.gov/pubmed/9478293?ordinalpos=12&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum Transcutaneous electrical nerve stimulation (TENS) as a pain-relief device in obstetrics and gynecology.] A study led by the