Lymph node cortical thickening is the appearance of thickening in the cortex of the lymph nodes and is an important indicator of the benign or malignant nature of the lymph nodes. It may be a symptom of reactive hyperplastic lymph nodes, malignant lymph nodes, tuberculous lymphadenitis and so on. 1. Reactive hyperplastic lymph nodes: most of the reactive hyperplastic lymph nodes are benign, usually caused by pharyngitis, upper respiratory tract infections, etc., which result in the reactive hyperplasia of lymphocytes and histiocytes in the lymph nodes. This results in lymphatic enlargement, leading to thickening of the lymph node cortex. 2. Malignant lymph nodes: malignant lymph nodes are often characterized by unclear demarcation between the cortex and the medulla, eccentric thickening of the lymph node cortex, and are often seen in multiple lymphatic enlargement throughout the body. 3. Tuberculous lymphadenitis: Tuberculous lymphadenitis, mostly seen in adolescents, is an inflammation of lymph nodes caused by Mycobacterium tuberculosis infection, which may also be manifested as thickening of lymph node cortex. Lymph node cortical thickening should go to the hospital in time to confirm the diagnosis, and follow the doctor’s instructions for treatment.