Hardness around the belly button with painful pressure may be due to the following diseases: First, it is due to intestinal flatulence. Due to intestinal dysfunction caused by intestinal flatulence will feel particularly hard around the navel, and there is pain on pressure; second, intestinal obstruction or intestinal spasm. Generally, intestinal obstruction and intestinal spasm are accompanied by hardening of the abdomen and rhythmic pain. A clear diagnosis can be made by palpation, auscultation, abdominal radiographs and X-rays; third, for children, if there is pain caused by enlarged mesenteric lymph nodes, they will also feel hardness around the navel and have pain on pressure. This is caused by inflammation after a cold, fever, or tonsillitis, which leads to mesenteric lymph node hyperplasia in children. The diagnosis can be clarified through laboratory tests and ultrasound.