If a lymph node does not go away but that it mean?

One or more: They become inflamed or enlarged in various diseases which may range from trivial throat infections or other infections, to life-threatening cancers.Also are they tender and how big they are and where they are located may have more of a clinical significance.If their are multiple that is more worrisome.Sometimes they antibiotics may be given and observed,sometimesthey need to be removed/biopsy