What are lymph nodes?

Lymph nodes are part of your immune system. These glands are found in your neck, over your clavicle, and in your armpits, groin, chest, and belly (abdomen). They act as filters for lymph fluid as it flows through your body. Lymph fluid contains white blood cells (neutrophils, lymphocytes, and other cells) that help the body fight infection and certain other diseases.

Why lymph nodes swell

Lymphadenopathy is very common. The glands often get larger during a viral or bacterial infection. It can happen during a cold, the flu, or strep throat. The nodes may swell in just one area of the body, such as the neck (localized). Or nodes may swell all over the body (generalized). The neck (cervical) lymph nodes are the most common site of lymphadenopathy.

What causes lymphadenopathy?

Dead cells and fluid build up in the lymph nodes as they help fight infection or disease. Immune cells gather in your lymph node when a germ or something foreign is introduced to your body. Immune cells mature in your lymph nodes, preparing them to attack and kill this outside threat to your body. This causes them to swell in size. Enlarged lymph nodes are often near the source of infection. This can help to find the cause of an infection. For example, swollen lymph nodes around the jaw may be because of an infection in the teeth or mouth. But lymphadenopathy may also be generalized. This is common in some viral illnesses such as infectious mononucleosis, HIV, or chickenpox (varicella).

Lymphadenopathy can also be caused by:

• Infection of a lymph node or small group of nodes (lymphadenitis).

• Cancer.

• Reactions to medicines such as antibiotics and certain blood pressure, gout, and seizure medicines. In rare cases, vaccinations can cause it.

• Other health conditions, such as lupus or sarcoidosis.

Symptoms of lymphadenopathy

Lymphadenopathy can cause symptoms such as:

• Lumps under the jaw, on the sides or back of the neck, in the armpits, in the groin, or in the chest or belly (abdomen).

• Pain or soreness in any of these areas.

• Redness or warmth in any of these areas.

• Drainage of pus from the gland out to the skin.

You may also have symptoms from an infection causing the swollen glands. Signs of an infection may include a fever, sore throat, body aches, and a cough.

Diagnosing lymphadenopathy

Your health care provider will ask about your health history and symptoms. They will give you a physical exam and check the areas where lymph nodes are enlarged. Your provider will check the size, texture, and location of the nodes. They will ask how long they have been swollen and if they are painful. You may be advised to have diagnostic tests and to see a specialist. The tests may include:

• Blood tests. These are done to check for signs of infection and other problems.

• Urine test. This is also done to check for infection and other problems.

• Chest X-ray, ultrasound, CT scan, or MRI scans. These tests can show enlarged lymph nodes or other problems.

• Lymph node aspiration or biopsy. The cause of enlarged lymph nodes may be checked by taking a sample of the cells and fluid with them. This is done either by placing a needle in the gland and withdrawing some of the contents (aspiration) or by removing the lymph node (excisional biopsy). In either case, samples of the lymph node are taken and checked in a lab for signs of infection, cancer, and other causes. You may be referred to other specialists for their opinion as well.

Treatment for lymphadenopathy

The treatment of enlarged lymph nodes depends on the cause. Enlarged lymph nodes are often harmless and go away without any treatment. Treatment is most often done on the cause of the enlarged nodes and may include:

• Antibiotic or antiviral medicine to treat a bacterial or viral infection.

• Incision and drainage of a lymph node for lymphadenitis.

• Other medicines or procedures to treat the cause of the enlarged nodes.

You may need a follow-up exam in 3 to 4 weeks to recheck enlarged nodes.

When to call your health care provider

Contact your health care provider if:

• Your symptoms get worse.

• You have new symptoms.

• You have a fever of 100.4°F (38°C) or higher, or as directed by your provider.

• Your lymph nodes are still swollen after 3 to 4 weeks.