Painful 1.4×0.7 cm lymph nodes in the armpit may be caused by inflammatory lymph node enlargement, cancerous lymph node enlargement and other diseases. 1. Inflammatory lymph node enlargement: it is because the sweat glands in the armpit are stimulated, causing folliculitis, axillary skin injury, acute mastitis, breast abscess, etc., which causes the lymph nodes in the armpit to nourish and multiply, resulting in inflammation and swelling, and painful symptoms, which can be treated by taking drugs such as amoxicillin and cefuroxime orally under the guidance of the doctor. 2. Enlargement of cancerous lymph nodes: It is due to the fact that the cancer cells of breast cancer metastasize from lymphatic vessels to axillary lymph nodes, which nourish and multiply in the axillary lymph nodes, leading to necrosis and fibrosis of axillary lymph nodes, resulting in cancerous enlargement of lymph nodes, which also oppresses the peripheral nerves and cutaneous nerves, resulting in painful symptoms. Drug treatment is not effective and can be treated by surgery. When the axillary 1.4×0.7 cm lymph nodes are painful, you should go to the hospital as soon as possible to clarify the cause of the disease, and carry out standardized treatment under the guidance of the doctor, so as not to delay the condition.