Tummy pain, back pain and swelling when you have your period are caused by congestion of the tissues in the uterus and pelvic cavity during the menstrual period. It can also be caused by cold, which causes poor blood circulation in the pelvic cavity and the resulting stomach pain and lumbar pain. When this happens, the first thing to do is to take more rest and apply appropriate hot compresses, either with hot water bags or warm packs. Diet must be careful not to eat cold, spicy, stimulating food. After these measures, if you do not see improvement, you can take appropriate pain medication after meals, or anal suppositories, which can significantly relieve the uncomfortable feeling of the abdomen. During the menstrual period, pay attention to more rest and do not strain. If the pain is severe and still does not improve after taking pain medication at home, you must promptly go to the hospital to see if there is endometriosis.