Blood flow signals in axillary lymph nodes suggest that infectious lesions or neoplastic lesions may occur in the lymph nodes there, and it is recommended to consult a doctor in time to find out the cause. 1. Lymphadenitis: Infectious lesions near the upper limbs and chest invade the axillary lymph nodes, which may cause inflammation of the lymph nodes, leading to filling of blood vessels in the lymph nodes, and ultrasound may show blood flow signals in the axillary lymph nodes, which is usually accompanied by systemic symptoms such as fever and fatigue. 2. Lymphoma: malignant tumors originated from lymph nodes and lymphatic tissues, clinical symptoms may appear painless axillary lymph node enlargement, usually accompanied by fever, lethargy and other systemic symptoms, ultrasound examination may lead to axillary lymph node blood flow signal. 3. Malignant tumor metastasis: malignant tumor metastasis can spread through the bloodstream, resulting in axillary lymph node metastasis, which leads to axillary lymph node enlargement. The enlarged lymph nodes are hard and difficult to push, and the lymph nodes will gradually merge and adhere to the skin and surrounding tissues. ultrasound examination may show that there are blood flow signals in the axillary lymph nodes. This phenomenon alone is not enough to diagnose the disease, should improve the relevant examination, the doctor to clarify the diagnosis, if necessary, targeted treatment.