The treatment of a hard lump behind the neck depends mainly on the cause of the lump. The first is lymphadenitis, which includes bacterial lymphadenitis and tuberculous lymphadenitis. Bacterial lymphadenitis is the most common and is often secondary to upper respiratory tract infection and can be cured in a short time with antibiotic treatment. Less common is tuberculous lymphadenitis, which is usually associated with pulmonary tuberculosis and requires regular anti-tuberculosis treatment. In case of cold abscess or rupture, adequate incision and drainage should be performed, and sinus scratching is required if necessary. The second type is sebaceous cysts or lipomas, which are more common body surface tumors. When sebaceous cysts or lipomas appear, they are usually removed with simple surgery. The third type, which is less common, is metastatic cancer. The type of lymph node cancer is determined through puncture biopsy, and then the primary lesion is found through various tests, and surgery, chemotherapy, and radiation therapy are taken according to the condition of the primary lesion.