Swollen Lymph Nodes
Medical Author: Siamak Nabili, MD, MPH
Medical Editor: Melissa Conrad Stöppler, MD
What are lymph nodes?
Lymph nodes are an important component of the body's immune system and help
in fighting infections.
They are small, soft, round or oval structures that are found throughout the
body and are connected to each other in chain-like (lymphatic chains) fashion by
channels similar to blood vessels. Each individual lymph node is covered
by a capsule made up of connective tissue.
Within the capsule, lymph nodes contain certain kinds of
immune cells. These
cells are mainly lymphocytes, which produce proteins that capture and fight
viruses and other microbes, and macrophages, which destroy and remove the
captured material.
Where are the lymph nodes located in the body?
Lymph nodes are located throughout the body. Some are directly under the skin
while others are deep inside the body. Even the most superficial (close to the
skin) lymph nodes are usually not visible or palpable (felt by touching), unless
they are swollen or enlarged for some reason.
They are connected to each other by loosely bound lymphatic vessels. Lymph
nodes generally coalesce in different regions in the body where they are
responsible for filtering the blood and performing their immunologic function
for that particular area of the body. Fluid from the lymphatic vessels
eventually feeds into the venous system (veins) in the body.

Next: What are the causes of swollen lymph nodes? »
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