In this Article

• What are lymph nodes?
• Where are the lymph nodes located in the body?
• What are the causes of swollen lymph nodes?
• What are the symptoms of swollen lymph nodes?
• How are swollen lymph nodes diagnosed?
• How are swollen lymph nodes treated?
• When should I see the doctor for swollen lymph nodes?
• What are the common lymph nodes that may get swollen?
• What are the complications of swollen lymph nodes?
• Swollen Lymph Nodes At A Glance
• Patient Discussions: Swollen Lymph Nodes - Describe Your Diagnosis
• Swollen Lymph Nodes Glossary
• Swollen Lymph Nodes Index

What are the causes of swollen lymph nodes?

There are may causes for swollen lymph nodes, sometimes referred to as "swollen glands" (lymphadenopathy or lymphadenitis). In general, lymph nodes become swollen when they are active either due to an infection, inflammation, or cancer.

Infections

Infections are the most common causes of swollen lymph nodes. Common infectious causes of swollen lymph nodes are viral, bacterial, parasites, and fungal.

Viruses

• infectious mononucleosis (mono),
  
  
• chickenpox,
  
  
• measles,
  
  
• HIV,
  
  
• herpes,
  
  
• common cold viruses,
  
  
• adenovirus, and
  
  
• many other viruses

Bacteria

• streptococcus,
  
  
• staphylococcus,
  
  
• cat scratch disease,
  
  
• syphilis,
  
  
• tuberculosis,
  
  
• chlamydia, and
  
  
• other sexually transmitted diseases

Parasites

• toxoplasmosis,
  
  
• leishmaniasis

Fungal:

• coccidiomycosis,
  
  
• histoplasmosis

Inflammation

Inflammatory and immunologic causes of swollen lymph nodes include diseases such as rheumatoid arthritis and lupus as well as sensitivity to some medications.

Cancer

Many cancers can also cause swelling of lymph nodes. These may be cancers that originate from the lymph nodes or blood cells such as lymphomas and leukemias. They may also be cancers that spread from another organ in the body (metastatic cancers). For example, breast cancer may spread to the nearest lymph nodes in the axilla (underarm), or lung cancer may spread to the lymph nodes around the collar bone.

Other causes of swollen lymph nodes

There are many other less common causes of swollen nodes, such as genetic lipid storage diseases, transplant graft rejections, sarcoidosis, and many other conditions.

It is also important to mention that swollen lymph nodes are not always a sign of an underlying disease. Sometimes they can be normal. For example, small (less than 1 centimeter), flat lymph nodes under the jaw (submandibular lymph nodes) in healthy children and young adults or small (up to 2 centimeters), groin lymph nodes (inguinal lymph nodes) in young individuals may be normal.

In many instances, a definitive cause for swollen lymph nodes may not be determined even after performing through examination and testing.

Swollen Lymph Nodes - Describe Your Diagnosis

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