The first day of menstruation is over, the abdomen is very swollen when pressed in. It may be caused by pelvic inflammatory disease, or it may be caused by other factors, such as ovarian masses. 1. Pelvic inflammatory disease: common clinical manifestations are lower abdominal pain, increased vaginal discharge, and in severe cases, fever, chills, headache, and lack of appetite. Generally need antibiotics for treatment, such as cefotaxime, metronidazole, etc., it is recommended to follow the doctor’s instructions to take drugs; if the formation of pelvic abscess, surgical treatment. 2. Ovarian mass: benign ovarian mass, may appear abdominal distension. Ultrasonography can detect the mass, and histopathologic examination can confirm the diagnosis. If the mass is small, it can be treated with medication such as ethinyl estradiol, etc. If the mass is large and there are other compression symptoms, surgery is recommended. In addition, ovarian malignant tumors, can also be bloated, ultrasound suggests mixed cystic and solid echoes, can improve PET-CT examination to make targeted treatment. If abdominal distension persists without relief or other symptoms appear, it is recommended to go to the hospital in time for examination, to clarify the cause of the disease, and then follow the doctor’s instructions for treatment.