Lymph nodes are found throughout your body. They are an important part of your immune system. Lymph nodes help your body recognize and fight germs, infections, and other foreign substances. The term "swollen glands" refers to enlargement of one or more lymph nodes. The medical name for swollen lymph nodes is lymphadenopathy. In a child, a node is considered enlarged if it is more than 1 centimeter (0.4 inch) wide.

Considerations
Common areas where the lymph nodes can be felt (with the fingers) include:
-- Groin
-- Armpit
-- Neck (there is a chain of lymph nodes on either side of the front of the neck, both sides of the neck, and down each side of the back of the neck)
-- Under the jaw and chin
-- Behind the ears
-- On the back of the head

Causes
Infections are the most common cause of swollen lymph nodes. Infections that can cause them include:
-- Abscessed or impacted tooth
-- Ear infection
-- Colds, flu, and other infections
-- Gingivitis
-- Mononucleosis
-- Mouth sores
-- Sexually Transmitted Diseases
-- Tonsillitis
-- Tuberculosis