You can determine whether the lymph nodes are enlarged through lymph node palpation and imaging. The best way to diagnose enlarged lymph nodes is to perform color ultrasound, especially for superficial lymph nodes. Under color ultrasound, the volume and size of the lymph nodes and their morphology and structure can be well evaluated, which is very important for judging whether there is any problem with the lymph nodes. In addition, other tests such as palpation can also be performed. Lymph node palpation can determine whether the superficial lymph nodes are enlarged or not. Under normal circumstances, except for a small number of superficial lymph nodes that can be palpated in the submandibular area, armpit and groin, other parts of the body cannot be palpated easily because the lymph nodes are relatively small, with diameters between 2~5mm, oval shaped, soft, flat, and with smooth surfaces, with no tenderness or pain, and with no adhesion to the surrounding tissues. However, if the diameter of the lymph nodes is more than 1~2cm on palpation, and the shape has changed, as well as the texture is more abnormal, the patient is usually called lymph node enlargement. Deep lymph node enlargement, such as mediastinal and abdominal lymph node enlargement, can only be detected with imaging studies. These include conventional plain films, ultrasound, CT, magnetic resonance imaging, and positron emission computed tomography (PET), while CT and ultrasound are simpler and more effective for abdominal and retroperitoneal lymph node enlargement. If patients find enlarged lymph nodes, they should go to the hospital in time to see a doctor, and then give targeted treatment after the cause is clarified.