The stomach lying down is flat, standing will bulge, if it is caused by the accumulation of abdominal fat, it is a normal phenomenon; ascites can also appear in the above symptoms, at this time more abnormal. 1. Normal situation: under normal physiological state, when standing due to gravity, will make the internal organs, abdominal fat has a slight sagging, for obesity or abdominal fat accumulation of the population is especially obvious, can appear when standing up the abdominal bulge of the situation. 2. Abnormal situation: when a moderate amount of ascites in the abdomen, due to the liquid in the abdominal cavity has a certain mobility, in the human body standing position, ascites accumulates in the lower abdomen, there will be abdominal bulge, and lying down, ascites will flow to the sides of the abdomen, abdominal bulge disappeared, the abdomen is flat. However, in the case of a large amount of ascites, the abdominal bulge occurs regardless of the position. If the above situation occurs and is accompanied by other uncomfortable symptoms, it is recommended to consult a doctor as soon as possible to clarify the cause under the guidance of a specialized physician, so as to avoid delaying the condition.