Cancer Symptoms Definition and Function of Lymph Nodes Lymph nodes and their link to cancer and infection By Lisa Fayed Lisa Fayed Lisa Fayed is a freelance medical writer, cancer educator and patient advocate. Learn about our editorial process Updated on October 22, 2021 Medically reviewed Verywell Health articles are reviewed by board-certified physicians and healthcare professionals. These medical reviewers confirm the content is thorough and accurate, reflecting the latest evidence-based research. Content is reviewed before publication and upon substantial updates. Learn more. by Rony Kampalath, MD Medically reviewed by Rony Kampalath, MD Rony Kampalath, MD, is a board-certified diagnostic radiologist specializing in imaging of the abdomen. Learn about our Medical Expert Board Print Table of Contents View All Table of Contents Definition and Function of Lymph Nodes in the Body Location of Lymph Nodes in the Body What Does an Enlarged Lymph Node Mean? My Tonsils Get Swollen Sometimes. Are Tonsils Lymph Nodes? How Lymph Nodes Are Tested Lymph nodes, also known as lymph glands, are oval-shaped masses of tissue in the body that serve an important role in protecting the body from infection and cancer. Here's what to know about the the role they play in infections and cancer. BSIP / Universal Images Group / Getty Images Definition and Function of Lymph Nodes in the Body Everyone has an extensive lymphatic system in their body, which consists of lymph nodes and lymph vessels. The lymph vessels carry a clear fluid called lymph that is collected from tissues throughout the body. Lymph contains cell wastes like cancer cells, bacteria, and viruses. This fluid then drains into lymph nodes where it's filtered by infection-fighting cells within the lymph nodes. These infection-fighting cells, also called white blood cells, destroy these foreign or "bad" cancer and infection-related cells. A sign that immune cells within a lymph node are fighting an infection or cancer is when they enlarge or become swollen. This is called lymphadenopathy, or adenopathy for short. Location of Lymph Nodes in the Body Lymph nodes are scattered throughout the body and located in groups, like in the armpit, groin, neck, pelvis, and abdomen. In some areas like the neck, the lymph nodes are located superficially and may be palpated — they feel like a pea or small bean. In other areas, like the abdomen or the chest, lymph nodes are located deeper and cannot be felt. What Does an Enlarged Lymph Node Mean? Enlarged or swollen lymph nodes can indicate infection, cancer, or another disease that affects the immune system. Most typically, swollen lymph nodes are related to a minor infection that the immune system is fighting. For example, paratracheal lymph nodes in the neck may become swollen and tender with an ear infection, sore throat, or tooth abscess. Once the infection has cleared, swollen lymph nodes shrink back to their normal size. Nodes that are immobile, hard, non-tender, and persistently enlarged are suspicious for cancer and should be evaluated by a healthcare provider. If cancer cells are present in a lymph node, they either spread there from the primary tumor—like a breast tumor that spreads to lymph nodes in the armpit—or they originate in the lymph node, and this is called lymphoma. If a person is diagnosed with a solid tumor, whether or not certain lymph nodes are enlarged is an important part of cancer staging, which affects how that cancer is treated. Causes of Swollen Lymph Nodes My Tonsils Get Swollen Sometimes. Are Tonsils Lymph Nodes? Tonsils are considered lymphatic organs and act as lymph nodes, although they are much larger. The spleen—an organ located on the left side of your abdomen—is also a lymphoid organ, although instead of filtering lymph fluid, it filters blood. How Lymph Nodes Are Tested If your healthcare provider is concerned that a lymph node is affected by cancer or infection, he or she will take a biopsy of the lymph node or remove the entire lymph node. The contents of the lymph node can then be examined under a microscope by a pathologist to see if cancer or infection-related cells are present. Was this page helpful? Thanks for your feedback! Limiting processed foods and red meats can help ward off cancer risk. These recipes focus on antioxidant-rich foods to better protect you and your loved ones. Sign up and get your guide! Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. What are your concerns? Other Inaccurate Hard to Understand Submit 3 Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. American Cancer Society. Lymph nodes and cancer. Lang S, Kansy B. Cervical lymph node diseases in children. GMS Curr Top Otorhinolaryngol Head Neck Surg. 2014;13:Doc08. doi:10.3205/cto000111 Gaddey HL, Riegel AM. Unexplained lymphadenopathy: evaluation and differential diagnosis. Am Fam Physician.