A 1998 review of over 200 articles in the English literature showed that evidence of a post-tubal sterilization syndrome (abnormal bleeding and/or pain, changes in sexual behavior and emotional health, increased premenstrual distress) aka post tubal syndrome, inconclusive for women over 30 years of age. The risk for women 20–29 years of age with pre-existing histories of menstrual dysfunction may be increased, "although they do not appear to undergo significant hormonal changes".[12] A 1993 study done in Japan found the symptoms of post-tubal ligation syndrome to be mild, and simple symptomatic treatment to be sufficient in most cases.[13] Discontinuing hormonal birth control has its own side effects, many of which are also commonly attributed to post-tubal sterilization syndrome.[14][15]