What are lymph nodes?

Your lymph nodes (or lymph glands) are small lumps of tissue that contain white blood cells, which fight infection. They are part of your body’s immune system. They filter your lymph fluid, which is composed of fluid and waste products created by the body’s tissues.

Lymph nodes help to fight infections. The glands near the infection can swell up (lymphadenopathy).

Where are my lymph nodes found?

Your lymph nodes are located throughout your body, including your:

• neck and back (cervical lymph nodes)
• armpits (axillary lymph nodes)
• groin
• stomach
• chest

Your lymph nodes drain lymph fluid from your nearby organs and areas of your body.

What is the role of my lymph nodes?

Your lymph fluid is carried to your lymph nodes by lymphatic vessels. The lymph nodes filter out harmful substances and waste products. They also contain immune cells called lymphocytes that destroy bacteria and cancer cells.

The filtered fluid is then returned to your blood.

If you have an infection or cancer, a lymph node may become swollen. If you are concerned about your lymph nodes, speak to your doctor.

Your lymph nodes are located throughout your body. They drain lymph fluid from your nearby organs or areas of your body.

What causes swollen lymph nodes?

Your lymph nodes may be swollen due to infection or inflammation. Swollen lymph nodes may be found in your neck, under the arms or anywhere else that there are lymph nodes.

Common causes of swollen lymph nodes are:

• viruses (such as glandular fever)
• bacterial infections (such as tonsillitis)
• some autoimmune conditions

Your lymph nodes can swell up to several centimetres. They may stay swollen for several weeks after an infection.

Having swollen lymph nodes is very rarely a sign of cancer.

How are lymph nodes and cancer related?

Sometimes cancer can start in your lymph nodes (such as in lymphoma). Some other types of cancer can also spread from one part of your body to another through your lymph nodes.

Your lymph nodes play an important role in cancer including its diagnosis and treatment. They provide some information on your chance of recovery.

If you have cancer, your doctors will examine your lymph nodes carefully to see whether they are affected by cancer. They can do this by:

• feeling the lymph nodes in your neck, armpits and groin
• getting scans, for example a CT scan
• taking a small piece of tissue (biopsy) of the lymph nodes near your cancer, and examining them under a microscope

These tests help doctors to work out the best treatment for you. They also tell the doctors if your cancer has spread.