Lymph nodes swell in
one location due to any injury, infection, or tumor developing in
the lymph node. Which lymph nodes are swollen can help identify the problem. Glands on either side of the neck, under the jaw, or behind the ears are swollen in 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.