Alternative Names: Lymphadenopathy
The lymphatic system is a complex network of thin vessels, valves, ducts, nodes and organs. It helps to protect and maintain the fluid environment of the body by producing, filtering and conveying lymph and by producing various immune blood cells. The lumps that you feel in your neck or under your jaw when you have a cold or a sore throat are called lymph nodes. Lymph nodes are part of the body's immune system. They help to destroy infectious germs, such as viruses (e.g. the common cold virus) and bacteria (e.g. strep). The lymph nodes make antibodies that will help keep you from being infected with a particular germ in the future.
The lymph system is present throughout the body. Common areas where enlarged lymph nodes can be felt (palpable nodes) include the groin area (inguinal region), armpit (axilla), the neck (there is a chain of lymph nodes on either side of the front of the neck, both sides of the neck, and down each side of the back of the neck), under the jaw and chin, behind the ears, and over the occiput (prominence on the back of the head). Their function is the same regardless of their location.
Lymph nodes play an important part in the body's defense against infection. Swelling might occur even if the infection is trivial or not apparent.
Lymphadenitis is an infection and inflammation of one or more of the lymph nodes and usually results from an infection that begins near a lymph node. Often caused by Staphylococcus aureus bacteria, this condition affects the nodes in the neck, groin and armpit. It sometimes strikes individuals who have had coronary artery bypasses using a saphenous vein from the leg: The removal of this vein is accompanied by removal of related structures of the lymphatic system, lowering immunity to infection.
Acute lymphangitis is a bacterial infection in the lymphatic vessels which is characterized by painful, red streaks below the skin surface. This is a potentially serious infection which can rapidly spread to the bloodstream and be fatal.
While lymph nodes are the most common cause of a lump or a bump in the neck, there are other, much less common causes, e.g., cysts from abnormalities of fetal development or thyroid gland enlargement. Usually, your doctor can tell the difference on a physical examination.
Swelling of lymph nodes generally results from localized or systemic infection, abscess formation, or malignancy; other causes of enlarged lymph nodes are extremely rare. By far the most common cause of lymph node enlargement is infection. As a rule, when swelling appears suddenly and is painful, it is usually caused by injury or an infection. Enlargement that comes on gradually and painlessly may result from malignancy or tumor.
Common causes of enlarged lymph nodes:
Lumps in the armpit (axilla) may arise from various causes, including:
In general, always check with your health care provider to determine the nature of the lump. Do not try to diagnose lumps without professional help.
For a lump in the armpit caused by an infected, painful gland, follow the instructions about the proper treatment for the underlying infection.
A lump in the armpit caused by a generalized viral infection will eventually disappear without therapy. A lump in the armpit caused by an allergic reaction will go away after the provoking substance is removed. No treatment is necessary for a lump in the armpit caused by normal breast tissue, and usually no treatment is necessary for a cyst. A lump in the armpit caused by a lipoma (fatty growth) is harmless, unless it grows so large that it causes discomfort. For a lump in the armpit caused by a malignancy, follow the appropriate cancer treatment recommended by a doctor.
Call your health care provider if: