What are Lymph Nodes?
Lymph nodes (erroneously called lymph glands) are a part of the lymphatic system, a component of the body's immune system. Swollen lymph nodes may signal an infection.
There are several groups of lymph nodes, which are small, bean-shaped, soft nodules of tissue. The ones most frequently enlarged or swollen are found in the neck (a chain of lymph nodes is located in the front of the neck, the sides of the neck, and the back of the neck behind the ears), under the chin, in the armpits, and in the groin. There is also a large group of lymph nodes in the chest and abdomen, which are sometimes found to be enlarged on X-rays or CT scans.
- The lymphatic system consists of nodes and ducts spread throughout the body. They bring the lymph [the tissue fluid surrounding the cells, which contains white blood cells (lymphocytes), fluid from the intestines (chyle), and some red blood cells] back into the circulation through the veins. Lymph contains a concentration of infectious and other foreign substances (antigens).
- Lymph nodes are small clusters of cells, surrounded by a capsule. Ducts go into and out of them. The cells in lymph nodes are lymphocytes, which produce antibodies (protein particles that bind foreign substances including infectious particles) and macrophages which digest the debris. They act as the "cleaner" cells of the body.
- The lymph nodes are a major site where foreign substances and infectious agents interact with the cells of the immune system. A major cluster of the lymph nodes is the spleen, which, apart from other functions, also helps fight infections and responds to foreign substances in the body.
What Causes Swollen Lymph Nodes?
Several mechanisms can cause the lymph nodes to enlarge (swell).
- Infection (lymphadenitis): This can increase the number of white blood cells, which multiply in response to stimulation with a foreign substance (antigen). Swollen lymph nodes under the arm (in the armpit) can occur due to infection or injury to the arm or hand. Some infections (mononucleosis or "mono," HIV, and fungal or parasitic infections) may cause generalized swelling of lymph nodes throughout the body.
- Virus: Immune reaction to a generalized infection in the body such as viral infections that can occur with the common cold as well as more serious infections such as HIV.
- Inflammation: Infiltration with inflammatory cells during infection or inflammation in a region of a given lymph node. Some immune disorders, such as lupus or rheumatoid arthritis, may also cause generalized lymph node swelling.
- Cancer: Infiltration with malignant cells (metastases) brought to the node with the lymph flowing from an area of certain types of cancer. In rare cases, breast cancer or lymphoma may cause swollen lymph nodes in the armpit. Rarely, a person may have a node or group of nodes that grows rapidly and becomes hard and can not be easily moved around under the skin. These may indicate a tumor.
- Cancer of the blood: Uncontrolled, malignant multiplication of lymphocytes as in lymphoma or leukemia.
Swollen Lymph Nodes Symptoms
- The symptoms of swollen lymph nodes depend upon both the location and cause of the enlargement.
- Patients may experience symptoms of an upper respiratory infection (runny nose, sore throat, fever) and feel slightly tender or painful nodes under the skin around the ears, under the chin, or on the upper part of the neck under the jaw.
- Sometimes there may be a skin infection or redness and streaking of the skin, and one may feel an enlarged node in the vicinity in the direction toward the heart.
- Swelling of a lymph node located deep inside the body may have different consequences from swelling of those just under the skin. The blockage in the flow of lymph from swelling in a deeper node may cause a swelling of a limb or, for example, swelling of lymph nodes in the lung could cause a chronic cough, even though you would not be able to feel a swollen node in that location.
- Generalized swelling of lymph nodes throughout the body may occur due to infection, systemic inflammation, or cancer.
How to Test Swollen Lymph Nodes
- The doctor will ask the person about any associated symptoms and perform a physical examination.
- Depending on the extent of the problem, the doctor may order blood tests, X-rays, and a CT scan of the affected area.
- On follow-up, a biopsy of the swollen node may be needed. A sample of the tissue may be taken out by withdrawing cells from the lymph node with a thin needle (fine needle aspiration or biopsy). In other cases a lymph node itself or a portion of a lymph node may be removed for examination. In all these cases the tissue is examined by a pathologist under a microscope to determine the cause of the swelling.
When to Seek Medical Care
Inflamed lymph nodes themselves are generally not a major concern, but if you have symptoms of another condition along with enlarged lymph nodes, consult your doctor:
- If the swelling of the nodes lasts for more than two weeks or you have symptoms such as weight loss, night sweats, fatigue, or fever
- If the nodes are hard, fixed to the skin, do not move, or are growing rapidly
- If you can feel swelling close to your collarbone or in the lower part of the neck
- If the overlying skin is red and inflamed and you suspect an infection
The diagnosis of swollen lymph nodes rarely requires emergency hospital treatment. The exceptions to this include a growing infection of the skin that requires treatment, a severely infected lymph node that needs to be drained, or severe pain. If a swollen lymph node in the neck makes breathing or swallowing difficult, seek medical treatment immediately.
Swollen Lymph Nodes Locations
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 neck.
- 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 lymphoma.
- 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 area.
- Glands above the collarbone (supraclavicular lymph nodes) may swell from an infection or tumor in the areas of the lungs, breasts, neck, or abdomen.
How to Treat Swollen Lymph Nodes
A lymph node that is rapidly growing over one to two days has a different cause and treatment than generalized swelling of lymph nodes that occurs over a few months. Tell a doctor about any rapidly growing nodes at the time of examination because this helps establish a diagnosis.
- Standard treatment for swollen lymph nodes may include pain relievers and medicine to lower a fever, such as ibuprofen (Advil, Motrin) and acetaminophen (Tylenol). Home remedies such as warm compresses and elevation may help reduce and resolve swelling.
- If the cause of the swelling is infection, the doctor may prescribe antibiotics or antiviral medications.
- If there is a localized pocket of infection (abscess), it may need to be drained by cutting open the skin, draining the infected fluids, and then filling the opening with packing.
- For swelling due to malignancy, the treatment may involve surgery, radiation, or chemotherapy.
- If a person has an immune disorder, he/she may be prescribed medication to help with the disease.
Swollen Lymph Nodes Self-Care at Home
If a person has symptoms of a cold or other minor infection for which they may or may not take antibiotics, it takes about two weeks for the nodes to return to normal size. No specific treatment is needed.
- If the nodes are small (less than 2 cm or 3/4 of an inch), are in the groin or under the chin, and you are a young adult, this is considered normal.
- Children tend to have a more active lymphatic system, so their nodes may feel enlarged.
Swollen Lymph Nodes Prognosis
In the majority of cases, swollen lymph nodes resolve with no other concerns.
However, in cases of serious systemic infections, patients with compromised immune systems, and patients with cancers, lymph node swelling may be chronic and may never resolve.
Reviewed on 8/30/2017
American Cancer Society. "Lymph Nodes and Cancer." 14 April 2015.
Johns Hopkins Medicine. "Lyphadenitis." 12 March 2016.