Lymph nodes often swell in one location when a problem such as an injury, infection, or tumor
develops in or near the lymph node. Which lymph nodes are swollen can help identify the problem.
The glands on either side of the neck, under the jaw, or behind the ears commonly swell when you have a cold or sore throat. Glands can also swell following an injury, such as a cut or bite, near the gland or when a tumor or infection occurs in the mouth, head, or neck.