The hardness around the belly button when a woman lies down may be caused by intestinal flatulence, indigestion, or pelvic mass, etc. It is recommended that the patient go to the hospital for an abdominal ultrasound in time. 1. Intestinal flatulence: Intestinal flatulence is a common symptom of indigestion, mainly due to the intestinal tract with food swallowed air, gas produced by fermentation in the intestinal tract. This leads to hardness around the navel. 2. Dyspepsia: patients with dyspepsia due to intestinal food is not timely decomposition, food in the intestinal fermentation will produce gas, which leads to the phenomenon of hardness of the patient’s abdomen. 3. Pelvic mass: such as uterine fibroids, malignant tumors and so on can cause pelvic mass, the patient may also be accompanied by abdominal pain, abdominal distension, lethargy and fatigue and other systemic symptoms. In addition, it is also necessary to see whether the days are not going to the toilet, there may be feces in the intestinal tract caused by the phenomenon of hardness around the navel, then, you need to defecate in a timely manner, usually pay attention to the diet of the light, eat less greasy food, and often do a little abdominal massage, to promote intestinal peristalsis. If you are still not feeling well, you need to go to the hospital in time to avoid delaying your condition.