A Quick Look at Your Lymph Nodes

Most of us have heard of lymph nodes, but few people ever stop to think about where they are or what they actually do.

Your body has hundreds of lymph nodes working as part of the lymphatic system. They are found in areas such as your neck, chest, armpits, abdomen, and groin. They help filter lymph fluid and play an important role in your immune system.

This chart gives you a simple way to see where many of the major groups of lymph nodes are located and why they matter. Take a few minutes to look it over. You may be surprised by just how much of your body is connected to this system.

Keep this chart handy as a quick reference, and share it with someone who might find it useful.

 

 

Inguinal Lymph Nodes

Inguinal lymph nodes are located in your groin, where your upper thighs meet your lower abdomen. They are part of your immune system and help filter lymph fluid from areas such as your legs, feet, genitals and nearby pelvic region.

Why do they swell?

In most cases, swollen inguinal lymph nodes are responding to an infection or irritation nearby. Common causes include skin infections, fungal infections, urinary tract infections and sexually transmitted infections. Even a small cut or irritated area on your leg or foot can cause a node to become swollen or tender.

Why does cancer come up so often?

Because lymph nodes can be involved when cancer spreads through the lymphatic system. Some cancers near the groin can spread to the inguinal nodes, and lymphoma can also cause them to enlarge. But a swollen groin lymph node does not automatically mean cancer. Infection is a much more common cause.

A node that keeps growing, feels hard or fixed in place, or remains swollen without an obvious reason should be checked by a healthcare professional. Night sweats, fever or unexplained weight loss are also worth mentioning to a doctor.

 

Popliteal Lymph Nodes

Popliteal lymph nodes are located behind your knee, in the hollow area known as the popliteal fossa. They are part of the lymphatic system and help filter lymph from the lower leg and foot.

What do they do?

These lymph nodes help immune cells filter lymph and respond to germs and other foreign or damaged material. Lymph from certain areas of the foot and lower leg can pass through the popliteal nodes before continuing toward the deeper lymph nodes in the groin.

Can you feel them?

Usually, you won’t notice your popliteal lymph nodes. If you feel a lump or swelling behind your knee, it may be a lymph node, but it could also be something else. The area contains several muscles, blood vessels and other structures, so a new or persistent lump is worth having checked if you’re unsure what it is.

 

Mesenteric Lymph Nodes

Mesenteric lymph nodes are located in the mesentery, the tissue that supports and connects your intestines inside your abdomen. They are part of the lymphatic and immune systems and help filter lymph coming from the intestines.

What do they do?

These lymph nodes help your immune system monitor what is coming from the digestive tract. They filter lymph and provide a place where immune cells can respond to bacteria, viruses and other foreign material.

Can mesenteric lymph nodes become swollen?

Yes. Mesenteric lymph nodes can become enlarged when there is inflammation or infection in the abdomen, including infections affecting the intestines. This can sometimes cause abdominal pain and fever, particularly in children.

Mesenteric lymph nodes can also show up on abdominal scans even when they are normal. Small nodes are a common finding on CT scans, so seeing the words “mesenteric lymph nodes” on a scan does not by itself mean something is wrong.

 

Mediastinal Lymph Nodes

Mediastinal lymph nodes are located in the mediastinum, the central area of your chest between your lungs. This area contains the heart, major blood vessels, trachea and esophagus. Groups of lymph nodes are located around these structures, including near the trachea, bronchi, esophagus and major blood vessels.

What do they do?

Mediastinal lymph nodes are part of your lymphatic and immune systems. They filter lymph fluid and help immune cells detect and respond to bacteria, viruses and other foreign material.

Lymph from the lungs and other structures in the chest passes through different groups of these nodes before continuing through the lymphatic system. The nodes are arranged in specific locations, which doctors use to describe their anatomy and findings on imaging studies such as CT scans.

Where are the main groups?

Mediastinal lymph nodes are found throughout the chest. Some are located alongside the trachea, some beneath where the trachea divides into the main bronchi, and others are positioned near the esophagus, aortic arch and pulmonary structures.

Because they are located deep inside the chest, mediastinal lymph nodes generally cannot be felt from the outside. They are usually evaluated with medical imaging when necessary.