Pain in the abdomen may be caused by cystitis, appendicitis, chronic pelvic inflammatory disease. 1. Cystitis: this disease is mainly due to the patient’s own low immunity, usually hold urine habits and other factors, leading to bacteria into the bladder after the inflammation induced. Patients often appear frequent urination, urinary urgency and other symptoms, at the same time, when the bladder is full or under the stimulation of inflammation, pressure on the perineum, bladder and other areas of pain, which is manifested in the pressure of abdominal pain. 2. Appendicitis: It is usually considered to be caused by the blockage of the appendix lumen and bacterial invasion, and it is also related to colds and improper diet. Patients often have pain in the right lower abdomen, which can be intermittent and repeated many times, and also have pain in the lower abdomen when pressed. 3. Chronic Pelvic Inflammatory Disease: This disease is mainly caused by Chlamydia trachomatis, Neisseria gonorrhoeae and other pathogenic infections, which often leads to increased vaginal secretions, lower abdominal distension, pain and other symptoms, and can be aggravated during activities and sexual life. Some patients may show pain in the abdomen when pressed. There are many clinical causes of abdominal pain, and it is recommended that patients first seek medical examination to clarify the specific cause of the disease.