How is the condition diagnosed?

Diagnosis begins with a history and physical exam. This may be all that is needed to make the diagnosis. In other cases, further testing is needed. Blood tests are commonly used to help figure out the cause. A blood test called a complete blood count, or CBC, can help figure out if an infection or blood cancer is present. Imaging tests, such as a chest x-ray, can help diagnose some infections and cancers. In some cases, a biopsy of a lymph node may be needed. This procedure involves removing a small piece of the swollen lymph node from the body. A needle is often used if the lymph node is close to the skin. The needle can be inserted through the skin and into the lymph node. A small piece of the lymph node is removed with the needle. In other cases, the skin may be cut open to remove a larger sample, or the entire lymph node may be removed. The sample or the entire lymph node can then be sent to the lab for further testing and examination.