Normally, the lymph nodes on both sides are the same. When the size of the lymph nodes on the right and left sides are not the same, it often suggests a lesion near the body. Lymph nodes serve to filter and remove foreign bodies, produce lymphocytes and antibodies, etc. They are generally located around blood vessels and are more densely distributed in depressions such as the armpits and groin. When a lesion occurs in a certain area, the lymph nodes around the lesion will remove the spreading viruses and bacteria, resulting in an increase in the number of cells in the lymph nodes and an increase in their size, which is manifested as enlarged lymph nodes. Therefore, enlarged lymph nodes can indicate inflammation or lesions in the surrounding tissues. When the lymph nodes on both sides of the body are not the same, it indicates inflammation or lesions on one side of the body. In clinical practice, ultrasound can show the size and nature of the lymph nodes better, thus facilitating the diagnosis and treatment of occult diseases. When lymph nodes are found to be enlarged, it is necessary to consult a doctor in time, complete the corresponding examination and make a clear diagnosis.