Learning About Your Lymphatic System

Lymph nodes throughout the body

What does it do?

The lymphatic system carries lymph fluid, nutrients, and waste material between the body tissues and the bloodstream. It's made up of a network of lymph nodes and vessels in the body.

  • Lymph nodes are small, bean-shaped glands. They filter lymph fluid and trap bacteria, viruses, and other substances. White blood cells called lymphocytes then destroy these trapped substances.
  • Lymph vessels carry the lymph fluid through the body.

This system is also part of the immune system. Your immune system helps your body fight disease.

What might happen?

When there is a problem in the body, such as an infection or cancer, the nearby lymph nodes may swell. The three most common sites of swollen lymph nodes are the neck, armpit, and groin.

  • The lymph nodes on either side of the neck, under the jaw, or behind the ears may swell when:
    • You have a cold or sore throat.
    • You have an injury such as a cut or bite near the node.
    • You have a tumour or infection in your mouth, head, or neck.
  • The lymph nodes in the armpit may swell from:
    • An injury or infection to the arm or hand.
    • Breast cancer or lymphoma, another type of cancer.
  • The lymph nodes in the groin may swell from:
    • An injury or infection in the foot, leg, groin, or genitals.
    • Testicular cancer, lymphoma, or melanoma skin cancer.
  • The lymph nodes above the collarbone may swell from an infection or tumour in the areas of the lungs, breasts, neck, or belly.
  • Lymph nodes in more than one area of the body may also swell. This may be caused by:
    • A viral infection, such as mononucleosis.
    • A bacterial infection, such as strep throat.
    • A cancer that has spread.

Other problems with the lymphatic system include:

  • Lymphoma. This is a type of cancer that affects the lymphatic system.
  • Cancers other than lymphoma. They can spread through the lymphatic system.
  • Lymphedema. It causes swelling in the arms and legs.

Is it an emergency?

If you or someone in your care has chest pains, difficulty breathing, or severe bleeding, it could be a life-threatening emergency. Call 9-1-1 or the local emergency number immediately.
If you are concerned about a possible poisoning or exposure to a toxic substance, call Poison Control now at 1-800-567-8911.

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