Sudden enlargement of the lower part of the ear root often recurs, which may be related to an acute attack of chronic mumps, or it may be caused by enlarged submandibular lymph nodes, sebaceous cysts and other reasons. 1. Acute attack of chronic parotitis: This disease is usually caused by bacterial infection, resulting in obstruction of the parotid duct. It has the characteristic of recurrent attack. When acute attack occurs, under the stimulating effect of inflammation, it may lead to sudden enlargement of the lower part of the patient’s ear root, which is often repeated, and may be accompanied by fever, headache and other symptoms. 2. Enlargement of submandibular lymph nodes: this disease is usually secondary to upper respiratory tract infections, thyroid diseases, lymphatic tuberculosis, mainly due to inflammation of lymph nodes, which may lead to sudden enlargement of the lower part of the ear, often recurring, and may be accompanied by symptoms such as pain on pressure. 3. Sebaceous cysts: When sebaceous cysts appear in the skin of the lower part of the ear root, it can lead to sudden enlargement of the lower part of the ear root. It is mainly caused by long-term inattention to local skin hygiene, trauma, infection and other reasons. If you don’t pay attention to the prevention of triggering factors for a long time, it will lead to the sudden enlargement of the lower part of the ear root often repeated. Sudden enlargement of the lower part of the ear may also be caused by other reasons, so it is necessary to consult a doctor for a systematic examination and standardized treatment after a clear diagnosis.