The common causes of a hard abdomen after a year of caesarean section are keloid generation, peritonitis and uterine cavity tumors. 1. Keloid generation: if the cesarean section one year hard abdomen, may be because the abdomen to do cesarean section surgery at the incision generated subcutaneous keloid, so feel the abdomen hard. 2. Peritonitis: when the abdominal cavity produces infection, triggering peritonitis, the patient will appear plate-like abdomen, that is, the abdominal wall muscles are straight and hard as a plank, feel the abdomen will feel hard. 3. Tumor in the uterine cavity: If there is a tumor in the uterine cavity one year after cesarean section, the tumor grows to a certain volume, expands the uterine cavity, and when you touch the abdomen, you will feel the tumor, and you will feel the hardness of the abdomen. If you have a hard abdomen one year after cesarean section, you need to communicate with your doctor in time to find out the reason.