Vague pain in the abdomen in the 4th month of pregnancy, consider a variety of conditions, commonly muscle fiber damage, pre-miscarriage or digestive system diseases, urinary and reproductive system diseases, etc. Details are as follows: 1, damaged muscle fibers: the abdomen becomes bigger in the 4th month of pregnancy has become more obvious, with the gradual growth of the fetus, the uterus gradually becomes bigger and stretches the muscle fibers, if the muscle fibers are damaged or slightly broken at this time, it will make the pregnant woman’s abdomen vaguely painful. At this time, attention should be paid to rest and reduce physical activity; 2. Pre-eclampsia miscarriage: vague abdominal pain is not necessarily pre-eclampsia miscarriage, but it is also important to pay attention to vigilance. If a pregnant woman has mild pain in the lower abdomen or lower back pain, and a small amount of dark red blood or bloody leucorrhea from the vagina, it is considered to be a pre-eclampsia miscarriage, and she should seek medical attention in time. In addition, endocrine abnormalities, severe malnutrition, smoking and drinking, emotional tension, etc. of pregnant women may easily lead to preterm abortion, so pregnant women should also pay attention to whether they have the above state in time; 3. Digestive system diseases: common acute or chronic gastroenteritis, pancreatitis, appendicitis, etc. If pregnant women do not have uncomfortable symptoms such as vaginal bleeding, muscle strains, etc., coupled with the usual poor intestines or recent poor diet, then consider digestive system disease. It is recommended to adjust the diet structure in time, avoid excessive drinking, etc. If the symptoms have a tendency to aggravate, it is recommended to consult a doctor in time to clarify the cause and then treat it. Under the guidance of a doctor, drugs that inhibit gastric acid secretion, such as omeprazole, lansoprazole, cimetidine, etc., or drugs that protect the gastric mucosa, such as bismuth potassium citrate, misoprostol, thioglycollate, etc., can be taken orally; 4. Diseases of the urinary and reproductive system: common tubitis, urinary tract infection, urinary tract stones, etc., often manifested as pain in the lower abdomen, accompanied by frequent urination, painful urination and other symptoms, it is recommended to seek medical attention in a timely manner to clarify the cause and then treat. The clinical use of topical drugs and oral drugs at the same time, oral drugs can choose metronidazole tablets or amoxicillin and other anti-inflammatory drugs, external use of potassium permanganate solution sitz bath treatment, can effectively inhibit the growth of fungi and bacteria, so as to relieve the inflammatory reaction. In daily life, we can prevent it by avoiding excessive sex and washing the vulva every day.