Two lumps on the left side of the neck may be caused by enlarged lymph nodes, sebaceous adenoma, lipoma and so on. 1. Enlarged lymph nodes: It is common that nearby infection leads to lymph node inflammation, such as tonsillitis, pharyngitis, boils, etc.; it may also be the enlargement of lymph nodes caused by lymphatic metastasis of nearby malignant tumors, such as thyroid cancer, laryngeal cancer, etc. 2. Sebaceous adenoma: it is a kind of benign tumor characterized by adenoid differentiation, related to the hyperplasia of sebaceous glands caused by abnormal tissue development, mainly manifested as skin papules or nodules. When two sebaceous adenomas appear on the left side of the neck, the above symptoms may appear. 3. Lipoma: The accumulation of fat cells under the skin is relatively large, resulting in lipoma. Localized lumps may form and usually do not cause pain. When there are two lipomas on the left side of the neck, the phenomenon of two lumps on the left side of the neck can appear. In addition, two lumps on the left side of the neck can also be seen in other diseases, such as subcutaneous fibroma and so on. It is recommended to go to the hospital in time and follow the doctor’s instructions for treatment to avoid delaying the condition.