What are lymph nodes?
Lymph nodes are
small, bean-shaped glands throughout the body. They are part of the
lymph system, which carries fluid (lymph fluid),
nutrients, and waste material between the body tissues and the bloodstream.
The lymph 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
Common sites for swollen lymph nodes include the neck,
groin, and underarms.
What does it mean when lymph nodes swell in two or more areas of the body?
When lymph nodes swell in two or more areas of the
body, it is called generalized lymphadenopathy. This may be caused by:
- A viral illness, such as
chickenpox (varicella), or
(Epstein-Barr virus), which results in fever, sore throat, and fatigue, or
cytomegalovirus (CMV), a viral infection that causes
symptoms similar to those of mononucleosis.
- A bacterial illness,
such as strep throat (caused by the
streptococcus bacterium) or
Lyme disease (a bacterial infection spread by certain
types of ticks).
- Side effects of phenytoin (Dilantin), a medicine
used to prevent
- Side effects of
measles-mumps-rubella (MMR) vaccination.
- Cancer, such as
Hodgkin's disease, and
Acquired immunodeficiency syndrome (AIDS), which
develops after a person contracts
HIV (human immunodeficiency virus). This virus attacks
the immune system, making it difficult for the body to fight off infection and
Syphilis, a sexually transmitted
How are swollen lymph nodes treated?
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 within 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.
Swollen Glands, Hernias, and Other Lumps Under the Skin