If a patient has a small nodule on the left side of the neck that can be felt and moved with the hand, it may be due to some weakness of the skin on the left side of the neck, such as where the skin behind the ear meets the skin of the neck, where the normal immune organ, the lymph node, can be palpated. However, if the skin around the nodule appears significantly red, swollen, or painful, or is clearly distributed around blood vessels, it may also be an enlarged lymph node. In addition, it may also be caused by diseases such as goiter.1. Swollen lymph nodes: If the lymph nodes are in the superficial skin area, they themselves are easy to find and can slide slightly, so they are easier to detect if they become enlarged. There are many causes of swollen lymph nodes, such as inflammatory enlargement caused by infection, and it may also be related to lymphoma, myeloma, lung cancer, liver cancer, kidney cancer, breast cancer, nasopharyngeal cancer metastasis, and abnormal cell proliferation, etc. Therefore, the treatment mainly adopts cause-specific treatment. First of all, the cause should be clarified. If the lymph node enlargement caused by inflammation is often accompanied by obvious local fever and swelling, antibiotics, such as penicillin and cephalosporin, are needed to control the infection, as well as non-steroidal anti-inflammatory analgesics for pain relief, such as acetaminophen and aspirin. If an abscess or even sepsis is formed, further surgical incision and drainage is required; 2. Enlarged thyroid gland: The thyroid gland is located approximately in the lateral front of the neck and is distributed to the left and right. According to the anatomical structure, because the thyroid gland is close to the throat and organs, it can feel moving up and down when making swallowing movements. If the left side of the thyroid gland is enlarged, the patient may find a nodular bump on the left side of the neck, and it may slide slightly when touched by hand. Diffuse goiter, nodular goiter, and hyperthyroidism can all cause it. Therefore, if you feel the nodule sliding significantly on its own when swallowing, you can promptly seek medical treatment in combination with CT and other examinations to clarify the cause. Generally, propylthiouracil, methimazole, methimazole, carbimazole and other drugs can be used for treatment, and if necessary, thyroidectomy can also be used; 3. Other diseases: common sebaceous cysts, lipomas, sebaceous adenomas, etc. If they occur on the left side of the neck, they can also be small nodule-like. And it usually has the characteristics of smooth texture, easy to push, etc., and can be felt by hand. Usually patients do not have special symptoms and do not affect their daily life, but if such lesions become abnormal and suddenly increase in size, they may compress the surrounding blood vessels and nerves and have adverse effects on the body, and in such cases, surgery is needed to remove the cysts and tumors. There are many reasons why a small nodule on the left side of the neck can be felt by hand and move, so patients can make a preliminary judgment based on the accompanying symptoms and current medical history, if the skin around the nodule has changed abnormally, or there is a significant increase in size, discomfort, etc., it is recommended to seek timely medical attention to improve the relevant examination to avoid delaying the treatment of the disease.