What can cause swollen lymph nodes?

Monitoring Centers: The lymphatic system absorbs and carries things too big to go into the arteries and veins like bacteria eaten by white cells and digested food. The lymph nodes "taste" the lymph to see if anything bad is there like bacteria, viruses, cancers, etc. When it detects a problem, it alerts the immune system and your body reacts. They enlarge in response to the inflammation they create when they react.

Monitoring Centers: Lymphatic system absorbs/carries things too big to go into the arteries/veins like bacteria eaten by white cells and digested food. Lymph nodes "taste" the lymph for anything bad like bacteria/viruses/cancers, etc. When it detects a problem, it alerts the immune system and your body reacts. They enlarge in response to the inflammation they create when they react. They shrink when all is well.

Many possibilities. : Possible causes are: 1) infection- viruses, e.g., mono, herpes, hiv; bacteria e.g., strep, staph, etc; inflammation from autoimmune disorders 2) primary malignancies e.g., lymphoma, hodgkins 3) secondary malignancies e.g., metastatic cancers- breast, lung cancer, others 4) rare inherited metabolism disorders 5) rare poorly characterized disorders e.g., angioimmunoblastic lymphadenopathy.