Swollen lymph nodes usually occur as a result of exposure to bacteria or viruses. When swollen lymph nodes are caused by an infection, this is known as lymphadenitis (lim-fad-uh-NIE-tis). Rarely, swollen lymph nodes are caused by cancer.

Your lymph nodes, also called lymph glands, play a vital role in your body's ability to fight off infections. They function as filters, trapping viruses, bacteria and other causes of illnesses before they can infect other parts of your body. Common areas where you might notice swollen lymph nodes include your neck, under your chin, in your armpits and in your groin.

In some cases, the passage of time and warm compresses may be all you need to treat swollen lymph nodes. Treatment of lymphadenitis depends on the cause.