Normal tissues of the human body have lymph nodes, lymph nodes are important immune organs of the human body, the baby suddenly grew a few lymph nodes first of all, it is considered to be caused by infection, but do not rule out lymphoma. It is recommended to consult a doctor in time to clarify the cause. 1. caused by infection: lymph node as an immune organ, in the early stage of human infection can be firstly manifested as sudden swelling of lymph nodes, and then the baby may have fever, poor mental state and other manifestations, considering that it is caused by viral or bacterial infection, need to consult a doctor in time, and under the guidance of the doctor to carry out anti-infection treatment. 2. Lymphoma: Lymphoma is a malignant tumor originated from lymph nodes or lymphatic tissues. Clinical painless and progressive lymph node enlargement is the main manifestation. This disease can occur at any age, so it is recommended to consult a doctor to exclude this disease. If your baby suddenly grows several lymph nodes, it is recommended to go to the hospital for medical examination to avoid delaying the condition and causing unnecessary harm to the body.