Hello and welcome to health care magic. Thanks for the query. Pain killers are not known to cause a gain in weight. On the contrary if taken in excess they cause gastritis and weight loss. There may be other reasons for weight gain like hypothyroidism or other endocrine disorder and this can be detected by blood tests. So it is better to get tested for these. Dysmenorrhea means pain during menses. It is just a symptom like say pain in head and the causes may be many. Retroverted uterus is one cause of dysmenorrhea. Other reasons may be adenomyosis, fibroids [non cancerous uterine tumors], endometriosis. As you have done ultrasound and there are no fibroids so this condition is ruled out. Adenomyosis may also cause dysmenorrhea in your case. Endometriosis is a condition where menstruation occurs inside the abdomen. It is associated with severe dysmenorrhea and the diagnosis is mainly by physical examination and laparoscopy. I suggest that you try to loose weight as this weight may be the cause of adenomyosis. It can also cause other problems like diabetes [raised blood sugar] and raised blood pressure. Follow a strict dietary regimen with no fats and sugars and exercise daily. The treatment of adenomyosis and endometriosis depends upon age, number of children and patients desire to preserve the uterus. In older females with completed family and age more than 45 a hysterectomy is a better option if the women desires. So this needs to be discussed with your treating gynecologist. I hope I was able to help you. Thanks for using HCM. Please do feel free to ask any more queries that you may have and I will be happy to help you. Dr Madhuri Bagde Consultant Ob Gy.