Lymph nodes, sometimes called lymph glands, are an important part of theimmune system.
Within lymph nodes are white blood cells calledlymphocytesthat help neutralize foreign agents like bacteria and viruses.
Swollen lymph nodes are a sign that the body is fighting an infection or disease.
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Some diseases can also directly affect lymph nodes, including cancers likelymphoma.
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What Are Lymph Nodes?
Lymph nodes are small, bean-shaped organs that are part of the lymphatic system.
Verywell / Brianna Gilmartin
What Are Lymph Nodes For?
It also generates heat that helps damage and destroy the invader.
Together, these effects cause lymph nodes to become red, swollen, and warma condition referred to aslymphadenopathyoradenopathy.
Once the foreign invader has been neutralized, the lymph node will return to its normal size.
How to Check For Swollen Lymph Nodes
Lymph nodes are strategically clustered throughout the body.
Some can cause extreme pain, especially those behind the ear that can compress theEustachian tubeand adjacent structures.
However, not all swollen lymph nodes are painful or readily noticed.
The same is true for certain chronic infections likeHIVthat can cause persistent, low-level inflammation.
It is not uncommon to find one in the armpit or neck and have no other symptoms.
A lymph node can also be visibly swollen but entirely painless.
This is often the case when the lymph node itself is subject to disease.
Swollen lymph nodes that are movable are more likely to be benign (non-cancerous).
Lymph nodes are clustered throughout the body in key locations.
Swollen lymph nodes in the armpits, neck, and groin can often be felt.
There are usually between 10 and 40 lymph nodes in the axilla.
The axillary lymph nodes are important in the diagnosis of breast cancer.
When cancer cells are shed from a breast tumor, they first travel to the axillary nodes.
Supraclavicular Lymph Nodes
Supraclavicular lymph nodesare located just above the collarbone (clavicle).
Mediastinal Lymph Nodes
Mediastinal lymph nodesreside in the center of the chest cavity between the lungs.
Checking mediastinal lymph nodes is essential to the staging of lung cancer and some lymphomas.
Inguinal Lymph Nodes
Inguinal lymph nodesare located in the groin.
These are the nodes to whichtesticular cancerfirst spreads.
They can only be seen in imaging studies.
Mesenteric Lymph Nodes
Mesenteric lymph nodeslie deep within the abdomen in the membranes that surround the intestine.
Pelvic lymph nodes are only seen in imaging studies.
Causes of Swollen Lymph Nodes
Many conditions can cause swollen lymph nodes directly or indirectly.
Some are relatively mild and treatable, while others are more serious.
If an infection is acute, the symptoms may be more noticeable due to the rapid rise of inflammation.
If the infection is chronic, symptoms may be less apparent because the underlying inflammation will generally be lower.
But the opposite can also be true in both cases.
Most escaped cancer cells are killed in the lymph nodes before they can start growing elsewhere.
But sometimes the lymph nodes are unable to contain the cells and are overtaken by cancer.
When this happens, the cancer can spread to other parts of the body (known asmetastasis).
In some cases, the immune assault directly targets lymph nodes.
At other times, the inflammation because of the immune assault can affect nearby lymph nodes.
It belongs to a group ofgranulomatousdiseasesthat cause hardened granules in organs.
If the lymph nodes are affected, they will often be stone-like and matted (melded in clusters).
Verywell / Brianna Gilmartin
When to See a Healthcare Provider
Swollen lymph nodes are common.
If the condition persists or is severe, you should have it looked at.
The sample can then be checked in the lab for cancer cells.
Lymphocytes are then recruited to control infection.
Cancer can also affect lymph nodes either as it spreads from a tumor or starts in the lymph nodes.
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