Swollen lymph nodes are very common and can occur in any group of people of any age and can be seen in a variety of diseases, both benign and malignant, so it is very important to pay attention to the causes of swollen lymph nodes and to seek timely diagnosis and confirmation to avoid misdiagnosis and omission. The following is a discussion of the common diseases of swollen lymph nodes. 1. Chronic lymphadenitis: most of them have obvious foci of infection and are often focal lymph nodes enlargement with pain and pressure pain, generally with a diameter of no more than 2~3cm, which will shrink after anti-inflammatory treatment. Enlarged inguinal lymph nodes, especially flat lymph nodes that have been present for a long time without change, are mostly of no importance. However, enlarged cervical and supraclavicular lymph nodes without obvious causes signify systemic lymphoid tissue hyperplasia disease, which should be taken seriously and further examined to determine. 2. Tuberculous lymphadenitis: with fever, excessive sweating, malaise, and increased blood sedimentation, mostly seen in young adults. It is often associated with pulmonary tuberculosis. The texture of lymph nodes is uneven, some parts are light (dry and cool-like changes), some parts are hard (fibrosis or calcification) and adhere to each other and to the skin, because of poor mobility, positive tuberculin test and tuberculosis antibody in blood. Malignant lymphoma: It can also be seen in any age group. The enlarged lymph nodes are often painless, progressively enlarged and can range from the size of a soybean to a date, moderately hard, tough, uniform and plump. They are generally not adherent to the skin, do not fuse with each other in the early and middle stages, and are movable. In the later stages, the lymph nodes can grow to a large size and fuse with each other to form a large mass with a diameter of 20 cm or more, invade the skin, and do not heal for a long time after rupture. In addition, it may invade the mediastinum, liver and spleen, and other organs. These include the lungs, gastrointestinal tract, skeletal system, skin, nervous system, and breast. The diagnosis requires biopsy. Clinically, malignant lymphoma is often misdiagnosed, and 70% to 80% of those with superficial lymph node enlargement as the first manifestation are diagnosed as lymphadenitis or lymph node tuberculosis at the initial diagnosis, resulting in delayed treatment. 4. Giant lymph node hyperplasia: It is a rare disease that is easily misdiagnosed. It often presents as enlarged lymph nodes of unknown origin, mainly invading the thoracic cavity, most often the mediastinum, but also the hilum and the lungs. Other sites of invasion include the neck, retroperitoneum, pelvis, axillae, and soft tissues. It is often misdiagnosed as thymoma, plasmacytoma, malignant lymphoma, etc. Understanding the pathology and clinical manifestations of this disease is extremely important for early diagnosis. 5. Pseudolymphoma: It often occurs in sites outside the lymph nodes, such as pseudolymphoma of the orbit and stomach, and lymphocytic polyps of the digestive tract, all of which can form masses. It is generally considered to be reactive hyperplasia, caused by inflammation. 6. Lymph node metastases: lymph nodes are often hard and uneven in texture, and the primary focus can be found. Rarely, they are generalized lymph node enlargement. 7.Acute leukemia and chronic lymphocytic leukemia: there are also often enlarged lymph nodes, especially acute lymphocytic leukemia common in children, with rapid clinical onset, often accompanied by fever, bleeding, enlarged liver and spleen, sternal pressure pain, etc. Hematology and bone marrow aspiration examination can confirm the diagnosis and identification. 8, nodular disease: less common in China, often invades the bilateral lung hilum in a radial pattern, accompanied by prolonged low-grade fever. All lymph nodes throughout the body can be enlarged, especially in front of and behind the ear, under the jaw, and next to the trachea. It is clinically difficult to distinguish from malignant lymphoma and requires skin testing and pathological examination for differentiation. Infectious mononucleosis: Mostly seen in young and middle-aged males, caused by EBV, may have fever and generalized lymph node enlargement, but the patient is often in good general condition and may have mild splenomegaly. The diagnosis can be confirmed by the presence of heterogeneous lymphocytes in the peripheral blood and a positive heterophilic agglutination test. 10, serum sickness: a disease that occurs after the patient uses serum products (such as tetanus antitoxin, rabies vaccine, etc.). A small number of patients have swollen lymph nodes as the first clinical symptoms. However, mostly the lymph nodes at the injection site and on the slide are swollen first. The diagnosis can be made based on the history of injection and fever, rash, and eosinophilia. Lymph node enlargement is very common, and the above ten diseases are listed in the hope that they can enlighten you to seek timely diagnosis, confirmation and differentiation in order to get timely and effective treatment.