Symptoms - Enlarged Lymph Nodes

Reviewed by: HU Medical Review Board | Last reviewed March 2022

All throughout your body, hundreds of lymph nodes are working to protect you from illness and infection. When they become swollen, it is a sign that your immune system is fighting off an infection or illness. Most of the time, it will be something like a common cold. But in rare cases, enlarged lymph nodes may signal a serious illness like cancer.

What is the lymphatic system?

The lymphatic system is 1 part of your immune system. It is made up of tissues, organs, and vessels. They work hand-in-hand to transport a colorless fluid (lymph) back to the bloodstream.1

Lymph carries white blood cells that protect the human body from infection by fighting viruses or bacteria in your blood. It is also responsible for sustaining body fluid levels, absorbing digestive fats, and getting rid of waste and abnormal cells from the lymph.1

The lymphatic system is made of several components, including:1

  • Lymph
  • Lymph nodes
  • Lymphatic organs (thymus, tonsils and adenoids, and spleen)
  • Lymphatic vessels
  • Collecting ducts
  • Bone marrow
  • Peyer’s patches
  • Appendix

What are lymph nodes?

Lymph nodes are bean-shaped glands in charge of sifting material carried through the lymphatic fluid (lymph). Lymph nodes have white blood cells that help defend the human body against infection and disease. Lymph nodes filter lymph by trapping germs and damaged or abnormal cells. Lymph nodes also help activate the immune response to get rid of these cells.2

Diseases and infections can include skin or wound infections, strep throat, HIV, chickenpox, ear infections, cold, and in rare cases, cancer.3

The human body has hundreds of lymph nodes linked to each other by lymph vessels. Our lymph nodes are located in the neck, armpits, chest, abdomen, and groin area.2

How does breast cancer spread in the lymph nodes?

Cancer appears in lymph nodes in 2 main ways:4

  • Starting from the lymph nodes themselves
  • Spreading from the lymph nodes from another part of the body

In most cases, though, cancer first appears somewhere else before spreading to the lymph nodes. This happens when cancer cells detach from the primary tumor and move to different areas through the lymph system or bloodstream.3

If cancer cells move via the lymph system, they are likely to settle in the lymph nodes. In most cases, when cancer spreads to the lymph nodes, it attacks the nodes close to the primary tumor. These are the nodes that have been most active in killing cancer cells.3

How do doctors find cancer in the lymph nodes?

Cancer is a disease that can lead to swelling of the lymph nodes. However, this rarely happens.3

Lymph nodes are tiny structures that are usually hard to find and not easily seen with the naked eye. However, when disease or an infection attacks the body, lymph nodes often get larger. And, those closer to the surface of the body swell so much that you can see or feel them.3

You will need to visit a doctor to find out if the swelling in your lymph nodes is a result of cancer or another disease or infection.4

At the hospital, your doctor will perform a biopsy. This means they will take out some lymph nodes or collect samples from various nodes using needles. A doctor will then look at the samples under a microscope to figure out if they contain cancer cells.3

By providing your email address, you are agreeing to our privacy policy.