What is the medical term for inflammation of the lymph nodes? Lymphadenitis Explained

October 2, 2025 •

5 min read

Over 600 lymph nodes exist throughout the human body as a critical part of the immune system. When these glands become inflamed and swollen, the medical term for inflammation of the lymph nodes is lymphadenitis. This condition typically signals that your body is actively fighting off an infection.

Quick Summary

Lymphadenitis is the medical term for enlarged and inflamed lymph nodes, often caused by an infection. Symptoms can include tenderness, redness, and swelling near the infection site. Treatment depends on the underlying cause, which may be viral, bacterial, or fungal.

Key Points

Lymphadenitis is the Medical Term: The specific medical term for inflammation of the lymph nodes is lymphadenitis.
Caused by Infection: This condition is typically a result of a bacterial, viral, or fungal infection spreading to the lymph nodes.
Recognizable Symptoms: Key symptoms include swollen, tender, and sometimes painful lymph nodes, often accompanied by redness and fever.
Localized vs. Generalized: It can be localized to a single area or generalized, affecting multiple groups of lymph nodes throughout the body.
Diagnosis is Essential: A healthcare provider diagnoses lymphadenitis through a physical exam, and may use blood tests or a biopsy to determine the cause.
Treatment Targets the Cause: Treatment depends on the source of the infection and may involve antibiotics for bacterial cases or supportive care for viral ones.
Know When to Seek Medical Care: Persistent swelling, hardness of the nodes, or accompanying symptoms like fever, weight loss, and night sweats warrant a doctor's visit.

What is Lymphadenitis?

Lymphadenitis refers to the infection and inflammation of one or more lymph nodes. These small, bean-shaped glands are vital components of the lymphatic system, a network that helps the body fight germs and infections. Located throughout the body, including the neck, armpits, and groin, lymph nodes produce and store white blood cells to filter fluid (lymph) and trap foreign invaders like bacteria and viruses. When they become overwhelmed fighting an infection, they swell and become tender, a condition known as lymphadenitis.

Causes of Lymphadenitis

Lymphadenitis is typically caused by an infection that spreads from another part of the body to the nearby lymph nodes. Depending on the type of infection, the cause can be categorized as bacterial, viral, or fungal.

Common infectious causes:

Bacterial infections: The most frequent culprits include Staphylococcus aureus and Streptococcus pyogenes, which can cause infections like strep throat or cellulitis. Other less common causes include cat-scratch disease (Bartonella) and tuberculosis.
Viral infections: Viruses such as those causing the common cold, measles, mumps, and infectious mononucleosis (Epstein-Barr virus) can lead to lymphadenitis. HIV is another viral cause, especially in cases of persistent generalized lymphadenopathy.
Fungal and parasitic infections: Though less common, these can also cause inflammation of the lymph nodes. Examples include histoplasmosis and toxoplasmosis.
Other conditions: While primarily infectious, lymphadenitis can sometimes be a sign of a more systemic issue, such as an autoimmune disease (e.g., lupus) or certain types of cancer (e.g., lymphoma, leukemia).

Symptoms of Lymphadenitis

Symptoms of lymphadenitis typically manifest near the site of the original infection. They can include:

Swollen, tender, or hard lymph nodes
Redness or red streaks on the skin over the affected lymph nodes
Warmth to the touch in the inflamed area
Fever and chills
Pain, especially when touching the swollen nodes
Formation of a pus-filled abscess in severe cases

The location of the swollen lymph nodes can often provide clues to the source of the infection. For instance, swollen nodes in the neck may indicate an ear or throat infection, while those in the armpit could be linked to an infection in the arm or breast.

Diagnosis and Treatment

Diagnosing lymphadenitis involves a comprehensive approach by a healthcare provider. After a physical exam to check for swollen and tender lymph nodes, further tests may be needed to pinpoint the cause and rule out more serious conditions.

Diagnostic steps typically include:

Medical history and physical exam: The doctor will inquire about your symptoms, travel history, and recent animal contact. They will also palpate the lymph nodes to check their size, texture, and tenderness.
Blood tests: A blood test, such as a complete blood count (CBC), can reveal signs of an active infection.
Imaging studies: An ultrasound or CT scan may be used, particularly for deeper lymph nodes, to help differentiate between benign and malignant causes.
Biopsy and culture: In some cases, a tissue sample from the lymph node or fluid from an abscess may be taken for a biopsy and culture. This is often the most definitive way to determine the exact cause of the inflammation.

Treatment for lymphadenitis focuses on addressing the underlying cause and relieving symptoms:

Antibiotics: For bacterial infections, a course of antibiotics is typically prescribed.
Antivirals or antifungals: These may be used for viral or fungal infections, respectively.
Pain management: Over-the-counter pain relievers, like ibuprofen or acetaminophen, can help manage pain and reduce fever.
Warm compresses: Applying a warm, moist compress to the affected area can help soothe pain and reduce swelling.
Surgical drainage: If an abscess forms, surgery may be necessary to drain the pus.
Observation: Mild viral infections may resolve on their own with rest and home care.

Lymphadenitis vs. Lymphadenopathy

While often used interchangeably by the public, lymphadenitis and lymphadenopathy have distinct medical meanings. The distinction is crucial for proper diagnosis and treatment.


Feature	Lymphadenitis	Lymphadenopathy
Definition	Inflammation and infection of the lymph nodes.	Enlargement or swelling of the lymph nodes.
Underlying Cause	Primarily caused by an infectious process (bacterial, viral, fungal).	A broader term that includes any cause of swollen lymph nodes, infectious or otherwise.
Key Characteristics	Swollen, often tender, red, and warm to the touch. May involve pus formation.	Simply refers to the enlarged state of the nodes. Can be hard, soft, painful, or painless.
Prognosis	Generally has a good prognosis with timely treatment addressing the infection.	Prognosis depends on the underlying cause, which could range from a benign infection to a serious condition like cancer.

Types of Lymphadenitis

In addition to the distinction from lymphadenopathy, lymphadenitis can be further classified based on its location and spread.

Localized Lymphadenitis: This is the most common type, affecting only one or a few lymph nodes in a single area, typically near the site of an initial infection. For example, a tooth abscess can cause localized lymphadenitis in the neck.
Generalized Lymphadenitis: This type involves swelling in two or more lymph node groups and can be a sign of a systemic infection or illness that affects the entire body. Conditions like mononucleosis or HIV can cause generalized lymphadenitis.
Mesenteric Lymphadenitis: A specific type of lymphadenitis affecting the lymph nodes in the mesentery, the tissue that attaches the intestine to the abdominal wall. It often mimics appendicitis and is more common in children after a viral infection.
Acute vs. Chronic: Doctors may also classify lymphadenitis based on its duration. Acute lymphadenitis is short-lived, while chronic cases persist longer, often associated with a long-term infection.

When to See a Doctor

While swollen glands often resolve on their own, especially with minor infections, it is important to know when to seek medical attention. You should contact a healthcare provider if:

The swelling appears for no obvious reason.
The lymph nodes continue to get larger or do not get smaller after several weeks.
The nodes feel hard, irregular, or fixed in place rather than soft and movable.
You experience associated symptoms like persistent fever, night sweats, or unexplained weight loss.
The swollen node is in the collarbone area or lower neck, as this location has a higher risk of malignancy.
The skin over the nodes is red and tender, or you have trouble breathing or swallowing.

Conclusion

Lymphadenitis, the medical term for inflammation of the lymph nodes, is a common condition typically signaling that the body is fighting an infection. With two main types, localized and generalized, and numerous potential causes, accurate diagnosis by a healthcare professional is key. Treatment varies depending on the underlying cause, ranging from antibiotics for bacterial infections to managing symptoms for viral ones. While most cases are benign and resolve with appropriate care, being aware of the signs that warrant a doctor's visit is important. For more information on the lymphatic system and lymphadenitis, see the resources provided by the University of Rochester Medical Center.

Understanding the Prognosis

For most cases of lymphadenitis caused by a common infection, the prognosis is excellent. With proper treatment of the root cause, the inflammation resolves, and the lymph nodes return to their normal size, though this can sometimes take weeks or months. In severe cases or when associated with more serious diseases, the prognosis depends on the underlying condition. Early medical intervention is crucial for a complete recovery and to prevent potential complications like abscess formation or sepsis. Maintaining good hygiene and seeking prompt medical care for any concerning symptoms are the best ways to ensure a positive outcome.

Frequently Asked Questions

No, lymphadenitis is specifically the inflammation of lymph nodes due to infection, while lymphadenopathy is a broader term for any enlargement of lymph nodes, regardless of the cause.

Bacterial and viral infections are the most common causes. For instance, Staphylococcus or Streptococcus bacteria can cause it, as can viruses responsible for the common cold or infectious mononucleosis.

While stress does not directly cause lymphadenitis, chronic stress can weaken the immune system, potentially making you more susceptible to infections that could then lead to swollen lymph nodes.

You should see a doctor if your swollen lymph nodes persist for more than two weeks, continue to increase in size, feel hard or fixed, or are accompanied by unexplained fever, weight loss, or night sweats.

Diagnosis typically involves a physical examination by a healthcare provider. Blood tests, imaging studies, or a biopsy may be performed to identify the underlying cause and rule out more serious conditions.

Treatment depends on the cause. For bacterial infections, antibiotics are used. For viral causes, supportive care like pain relief and warm compresses may be recommended. In some cases, an abscess may need to be drained surgically.

In most cases, lymphadenitis is not caused by cancer. However, persistently swollen or hard lymph nodes, especially if they are painless, can sometimes be a symptom of a more serious condition like lymphoma or metastatic cancer.

While not always preventable, maintaining good hygiene, promptly cleaning cuts or scrapes with antiseptic, and seeking early treatment for infections can help prevent lymphadenitis.