Lymph nodes are
small, bean-shaped glands throughout the body. They are part of the
lymphatic system, which carries fluid (lymph fluid),
nutrients, and waste material between the body tissues and the bloodstream.
The lymphatic system is an important part of the
immune system, the body's defense system against
disease. The lymph nodes filter lymph fluid as it flows through them, trapping
bacteria, viruses, and other foreign substances, which are then destroyed by
special white blood cells called lymphocytes.
Lymph nodes may be
found singly or in groups. And they may be as small as the head of a pin or as
large as an olive. Groups of lymph nodes can be felt in the neck, groin, and
underarms. Lymph nodes generally are not tender or painful. Most lymph nodes in
the body cannot be felt.
What causes swollen lymph nodes?
Lymph nodes often
swell in one location when a problem such as an injury, infection, or tumor
develops in or near the lymph node. Which lymph nodes are swollen can help
identify the problem.
The glands on either side of the neck, under
the jaw, or behind the ears commonly swell when you have a cold or sore throat.
Glands can also swell following an injury, such as a cut or bite, near the
gland or when a tumor or infection occurs in the mouth, head, or
Glands in the armpit (axillary lymph nodes) may swell from an
injury or infection to the arm or hand. A rare cause of axillary swelling may
be breast cancer or
The lymph nodes in the groin
(femoral or inguinal lymph nodes) may swell from an injury or infection in the
foot, leg, groin, or genitals. In rare cases, testicular cancer, lymphoma, or
melanoma may cause a lump in this
Glands above the collarbone (supraclavicular lymph nodes) may
swell from an infection or tumor in the areas of the lungs, breasts, neck, or
swollen glands focuses on treating the cause. For example, a bacterial
infection may be treated with antibiotics, while a viral infection often goes
away on its own. If cancer is suspected, a
biopsy may be done to confirm the diagnosis.
Any swollen lymph nodes that don't go away or return to normal size over
about a month should be checked by your doctor.
How long will lymph nodes remain swollen?
nodes may remain swollen or firm long after an initial infection is gone. This
is especially true in children, whose glands may decrease in size while
remaining firm and visible for many weeks.
How this information was developed to help you make better health decisions.