Sitting up stomach pain lying down does not hurt may be related to pathological factors such as intestinal polyps, peptic ulcer, gastroptosis, gynecological diseases. 1. intestinal polyps: mainly caused by chronic inflammatory stimulation, mostly associated with poor dietary habits, sitting up position change may compress the intestinal mucosa, very easy to pull the intestinal wall causing abdominal discomfort, lying down symptoms can be alleviated. 2. Peptic ulcer: mainly in the stomach and duodenum, mostly associated with Helicobacter pylori infection, nervousness, etc., can cause abdominal pain when sitting, lying down without pain, can also be accompanied by heartburn, acid reflux and other discomforts. 3. Gastric ptosis: If you suffer from gastric ptosis, the great curvature of the stomach can reach the pelvis when you stand up, and the lowest part of the curvature of the stomach can fall to the part below the iliac crest line, which may be related to prolonged bed-resting, emaciation and so on, and it can cause pain in the abdomen when you stand up, which can be relieved when you lie down. 4. Gynecological diseases: such as uterine adnexal inflammation, ovarian cyst torsion, etc. can stimulate the vagina and pelvic cavity caused by congestion and edema, the symptoms of abdominal pain, abdominal pressure is greater when sitting, and lying down when the abdominal pressure reduces the pain symptom can be relieved. If the symptoms of sitting up and lying down without pain persist, it is recommended to go to the hospital in a timely manner to improve the abdominal ultrasound and other examinations to identify the cause of pain and actively treat it, so as not to delay the condition.