It is a manifestation of poor spleen and stomach function and insufficient gastric motility. Poor spleen and stomach may be caused by many reasons. There are usually the following possibilities:

1. Caught a cold. Body cold, cold accumulated in the spleen and stomach, leading to the damage of stomach yang, can not work normally. 2. Not having a good rest. The body is too tired and the qi and blood are insufficient, which leads to insufficient energy in the stomach and insufficient gastric motility.

It is easy to catch a cold.