Wake up in the middle of the night stomach can not say uncomfortable is duodenal ballooning, duodenal ulcer caused by some people with abdominal cold related. The human body will be in the peak of secretion of stomach acid a few hours after going to sleep, the concentration of stomach acid is relatively high, because there is no food neutralization, so it will be discharged directly into the duodenum, when the duodenum is suffering from duodenal bullae, duodenal ulcer disease, will cause spasm and contraction of the intestinal wall because of the contact between the duodenal mucosa and stomach acid, causing stomach discomfort. Some people do not do a good job of keeping the abdomen warm at night or sleep under the air conditioner, which will lead to cold and cold abdomen, the blood circulation of the gastric mucosa will be affected, due to local ischemia, lack of oxygen, resulting in smooth muscle spasm, contraction, the body will appear stomach discomfort.