What is lymphadenitis?

Lymphadenitis is the medical term for an infection in one or more lymph nodes. Lymph nodes are filled with white blood cells that help your body fight off infections. When lymph nodes become infected, it's usually because an infection started somewhere else in your body.

You have about 600 lymph nodes in your body, but normal lymph nodes may only be felt below your jaw, under your arms, and in your groin area.

A normal lymph node is small and firm. When lymph nodes become infected, they usually increase in size and may be felt in other areas of your body during a physical exam.

Infections that spread to lymph nodes are usually caused by bacteria, viruses, or fungi. It is important to learn how the infection spread into your lymph nodes so that the right treatment can be started.

Lymphadenitis can be one of two types:

  • Localized lymphadenitis. This is the most common type. Localized lymphadenitis involves one or just a few nodes that are close to the area where the infection started. For example, nodes enlarged because of a tonsil infection may be felt in the neck area.
  • Generalized lymphadenitis. This type of lymph node infection occurs in two or more lymph node groups and may be caused by an infection that spreads through the bloodstream or another illness that affects the whole body.

What causes lymphadenitis?

Lymphadenitis occurs when one or more lymph nodes are infected by a bacteria, virus, or fungus. When lymph nodes become infected, it's usually because an infection started somewhere else in your body.

What are the symptoms of lymphadenitis?

The main symptom of lymphadenitis is enlarged lymph nodes. A lymph node is considered enlarged if it is about one-half inch wide. Symptoms caused by an infected lymph node or group of nodes may include:

  • Nodes that increase in size suddenly
  • Nodes that are painful to touch
  • Nodes that are soft or matted together
  • Redness or red streaking of the skin over nodes
  • Nodes that are filled with pus (an abscess)
  • Fluid that drains from the nodes to the skin

Lymphadenitis may also cause symptoms related to the underlying infection, such as a sore throat, fever, night sweats, fatigue, or weight loss.

The symptoms of lymphadenitis may resemble other medical conditions or problems. Always consult your health care provider for a diagnosis.

How is lymphadenitis diagnosed?

If you have lymphadenitis, the most important parts of your diagnosis are usually your history and the physical exam done by your health care provider. You may be asked about symptoms you're feeling, such as chills and fever, any recent travel, any breaks in your skin, and recent contact with cats or other animals. Then, during the physical exam, your health care provider will look for signs of infection near the enlarged lymph nodes.

These tests may be needed to help make the diagnosis:

  • Blood tests to look for infection
  • Taking a piece of the lymph node or fluid from inside the lymph node to study under a microscope
  • Placing fluid from the lymph node into a culture to see what type of germs grow

How is lymphadenitis treated?

Specific treatment for lymphadenitis will be determined by your health care provider based on the following:

  • The extent of the problem
  • Your age, overall health, and medical history
  • Your tolerance for specific medications, procedures, or therapies
  • Expectations for the course of the disorder
  • The opinion of the health care providers involved in your care
  • Your opinion and preference

The exact type of treatment depends on what type of infection has spread into your lymph nodes. Once an infection has spread into some lymph nodes, it can spread quickly to others and to other parts of your body, so it's important to find the cause of the infection and start treatment quickly.

Treatment for lymphadenitis may include:

  • Antibiotics given by mouth or injection to fight an infection caused by bacteria
  • Medication to control pain and fever
  • Medication to reduce swelling
  • Surgery to drain a lymph node that has filled with pus

Can lymphadenitis be prevented?

The best way to prevent lymphadenitis is to see your health care provider at the first sign of any infection or if you notice a tender swelling that feels like a little lump just beneath your skin. Make sure to cleanse and use antiseptic on any scratches or breaks in your skin and always practice good hygiene.

Living with lymphadenitis?

Take all your medications exactly as prescribed and keep all your follow-up appointments; don't use any over-the-counter medications without first talking to your health care provider. Cool compresses and elevating the affected part of your body may help relieve pain and swelling while your medications are doing their work.

In most cases lymphadenitis clears up quickly with proper treatment, but it may take more time for lymph node swelling to go away. Be sure to let your health care provider know if your lymphadenitis symptoms come back. 

When should I call my health care provider?

If your symptoms get worse or you have new symptoms, call your health care provider. 

Key points

  • Lymphadenitis is an infection in one or more lymph nodes.
  • When lymph nodes become infected, it's usually because an infection started somewhere else in your body.
  • Lymphadenitis can cause lymph nodes to become enlarged, red, or tender.
  • Treatment may include antibiotics, and medications to control pain and fever.
  • Early treatment of infections can prevent the development of lympadenitis.


Next steps

Tips to help you get the most from a visit to your health care provider:

  • Before your visit, write down questions you want answered.
  • Bring someone with you to help you ask questions and remember what your provider tells you.
  • At the visit, write down the names of new medicines, treatments, or tests, and any new instructions your provider gives you.
  • If you have a follow-up appointment, write down the date, time, and purpose for that visit.
  • Know how you can contact your provider if you have questions.

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