Many children visit the clinic with various symptoms, such as abdominal pain, fever, vomiting, constipation, etc. Ultrasound reveals enlarged mesenteric lymph nodes, some up to 2 cm in diameter, and parents are nervous about the serious impact on their children’s health. In normal people, mesenteric lymph nodes are found in various sizes and in large numbers, especially in children. The main function of mesenteric lymph nodes is immune surveillance and removal of pathogenic microorganisms that enter the body through the intestine or bloodstream. Another function is the transfer of nutrients digested and absorbed by the intestine via the lymphatic vessels, which is extremely important for the growth and development of children. If a child is infected with viruses or bacteria, such as the common cold, enteritis, appendicitis, etc., it can lead to enlarged mesenteric lymph nodes, which manifest as intermittent abdominal pain, sometimes more intense, and accompanied by fever and vomiting. In this case, it is usually necessary to hang saline for a few days to reduce inflammation in order to slowly relieve the symptoms, but the lymph nodes do not necessarily shrink. Parents then get very worried and I often see this problem. In fact, the presence of swollen lymph nodes does not matter, as long as the child gets better and no symptoms appear, just leave it alone, the lymph nodes will usually shrink on their own when they get older.