Lymphadenitis is the medical term for inflamed and enlarged lymph nodes. It is usually due to an infection. Lymph nodes are filled with white blood cells that help your body fight infections. When lymph nodes become infected, it's usually because an infection started somewhere else in your body. Less often, lymph nodes can enlarge due to cancer.

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

A normal lymph node is small and soft. When lymph nodes become infected, they usually increase in size, become sore, may be firm to the touch, 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, a virus, or a fungus. 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. It may be caused by an infection that spreads through the bloodstream or another illness that affects the whole body.

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

Lymphadenitis mainly causes enlarged, sore lymph nodes. A lymph node is considered enlarged if it is about 1/2 inch wide. Symptoms caused by an infected lymph node or group of nodes may include:

• Nodes that increase in size
• 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

These symptoms may look like other health problems. Always see your doctor for a diagnosis.

If you have lymphadenitis, your doctor will ask about your health history and give you a physical exam. You may be asked about your symptoms, such as chills and fever, any recent travel, any breaks in your skin, and recent contact with cats or other animals. During the exam, your doctor will look for signs of infection near the enlarged lymph nodes.

These tests may be needed to help make the diagnosis:

• Drawing blood to look for an infection
• Checking for germs at another site of the body that may appear infected near the lymph nodes. These tests include a throat culture, culture of pus from a wound, or checking for sexually transmitted infections.
• Taking a sample of tissue from 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

Treatment will depend on your symptoms, age, and general health. It will also depend on how severe the condition is.

The exact type of treatment depends on what type of infection has spread into your lymph nodes. At times, if an infection spreads into lymph nodes, it can spread quickly to other lymph nodes and other parts of your body. So it may be important to find the cause of the infection and start treatment quickly.

Treatment may include:

• Antibiotics, antivirals, or antifungals given by mouth, I.V., or injection. Which of these you get depends on the type of germ causing the infection.
• Medicine to control pain and fever
• Medicine to reduce swelling
• Surgery to drain a lymph node that has filled with pus

The best way to prevent lymphadenitis is to see your doctor at the first sign of any infection or if you notice a sore 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, especially frequent handwashing.

Take all your medicines exactly as prescribed and keep all your follow-up appointments. Don't use any over-the-counter medicines without first talking to your doctor. Applying cool compresses and elevating the affected part of your body may help relieve pain and swelling while your medicines are doing their work.

In most cases, lymphadenitis clears up quickly with correct treatment. But it may take more time for lymph node swelling to go away. Sometimes a previously infected lymph node may stay enlarged for a long time after the infection has gone away. Be sure to let your doctor know if your lymphadenitis symptoms come back.

If your symptoms get worse or you have new symptoms, contact your doctor.

• 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 sore.
• Treatment may include antibiotics and medicines to control pain and fever.
• Early treatment of infections can prevent the development of lymphadenitis.

Tips to help you get the most from a visit to your doctor:

• Know the reason for your visit and what you want to happen.
• Before your visit, write down questions you want answered.
• Bring someone with you to help you ask questions and remember what your doctor tells you.
• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your doctor gives you.
• Know why a new medicine or treatment is prescribed and how it will help you. Also know what the side effects are.
• Ask if your condition can be treated in other ways.
• Know why a test or procedure is recommended and what the results could mean.
• Know what to expect if you do not take the medicine or have the test or procedure.
• If you have a follow-up appointment, write down the date, time, and purpose for that visit.
• Know how you can contact your doctor if you have questions.