Pain in the mandibular lymph nodes may be due to inflammation of the mandibular lymph nodes. If there is progressive enlargement with pain, with or without fluctuating sensation, it is necessary to seek medical attention and perform ultrasound examination. The pain may be caused by the early spread of mumps to the mandibular lymph nodes, by systemic inflammation, or by the enlargement of the mandibular lymph nodes due to inflammation of the respiratory tract or oral cavity, or by the enlargement of the lymph nodes due to malignant diseases of the blood system. Tuberculosis infection combined with bacterial infection may also be accompanied by enlargement of lymph nodes with pain.