Fullness of the lymph nodes in the armpits generally means that the lymph nodes in the armpits appear enlarged, and there are generally two factors that can cause this. 1. caused by inflammation, lymph nodes play an important role in the body’s anti-inflammatory process, when the body’s inflammation is more serious, the immune system needs to be activated, which includes the lymph nodes, and they can improve the immune system when they are enlarged. 2. Metastasis of cancer can also lead to enlarged lymph nodes, because the immune system is an important pathway in the process of metastasis of cancer cells, and the lymph in other places can also be enlarged due to the erosion of cancer cells. In order to identify the above two situations, we need to have further examination, we can check the blood routine to see the number of white blood cells, and we can also perform ultrasound-guided puncture of enlarged lymph nodes and then send them for pathological examination, which can clearly diagnose what is the cause of enlarged lymph nodes.