The normal or not of the baby armpit lymph nodes is related to the size of the lymph nodes, lymph node diameter ≤ 1cm is normal, if it is larger than 1cm, it may be due to lymphadenitis. 1. Lymph node diameter ≤ 1cm: small children appear such size of lymph nodes is normal, is normal lymphatic system is the body’s immune system to the outside world, can resist the influence of various external factors, the lymphatic system is the body’s immune system to the outside world. 2. Lymph node diameter >1cm: small children with enlarged lymph nodes, because the child contact with external bacteria, viruses, the lymphatic system development and maturation of the body’s immune system earlier than the whole body, so the lymphatic system in the small children encountered external bacteria, viruses will protect the body to play their own role in the lymph node reactivity increased. It is recommended that parents take their children to a children’s hospital when they have large lymph nodes, and use appropriate anti-inflammatory drugs under the guidance of a specialized doctor.