What Is Lymphadenitis? - Definition, Symptoms & Treatment

Instructor: Danielle Haak

Danielle has a PhD in Natural Resource Sciences and a MSc in Biological Sciences

The lymph nodes are responsible for fighting off infections of the body. But what happens when the lymph nodes become inflamed? Read this lesson to learn about lymphadenitis, its causes, and treatment options.

What is Lymphadenitis?

The lymph nodes are small organs around the body that are responsible for fighting infections. They house the fighter cells and release them when an infection is detected. You may be familiar with having swollen lymph nodes (commonly felt in the neck) when you are sick. Lymph nodes becoming inflamed and tender during an infection is a condition called lymphadenitis. Even fighting the flu or a common cold can result in swelling of the lymph nodes, causing lymphadenitis.

Causes of Lymphadenitis

As previously mentioned, lymph nodes are responsible for releasing the cells that defend against infections. Though the lymph nodes are found in various spots throughout your body, such as the armpits and neck, they are connected by lymphatic vessels. The lymphatic vessels carry lymph, which is the fluid containing the white blood cells (the infection-fighting cells) and diseased tissue that needs to be disposed of from the body. When you are sick, the body is in overdrive mode, working to fight the infection. This leads to the lymph nodes becoming flushed with both lymph and the waste tissue, causing the lymph nodes to become inflamed and swollen.

Symptoms of Lymphadenitis

When the lymph nodes become inflamed, they swell and grow in size. This often results in them become painful and sore, especially to the touch. Sometimes, they even become visible from outside the body and may be hard to the touch. Swollen lymph nodes can lead to swelling in the limbs (due to a possible blockage in the lymph system), night sweats, and general discomfort. Lymphadenitis usually accompanies an infection like the common cold or the flu, so symptoms such as a sore throat, runny nose, and fever may also be present.

Lymphadenitis results in swollen lymph nodes, which can become visible from outside the body.
Lymphadenitis symptoms

Treatment Options

A doctor can diagnose lymphadenitis simply by completing a physical exam; he or she will be able to feel the lymph nodes through the skin. If there is no apparent infection (like a cold), the physician may request a lymph node biopsy to rule out possible causes and identify the underlying cause. A biopsy is simply a sampling of tissue that can then be tested.

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