The Causes of Enlarged Lymph Nodes

When lymph nodes increase in size, they are called enlarged lymph nodes. When enlarged nodes can be felt by the healthcare provider (in areas like the neck, armpits, and groin), they are called palpable lymph nodes.

Lymph nodes contain white blood cells (WBCs), especially the WBCs known as lymphocytes. Different types of lymphocytes grow and mature inside a lymph node, and these immune cells help the body fight infections.

Female doctor examining her patient
skynesher / Vetta / Getty Images 

Lymph nodes are connected to each other by lymph channels called the lymphatics—small tubes (like blood vessels)—through which lymph fluid, as well as proteins and other substances, moves from one part of the body to another.

Lymph nodes in different parts of the body are named differently

More on Enlarged Nodes

Lymph nodes can increase in size in a number of conditions. Infections, cancer, and many immune diseases can affect lymph cells and cause an enlargement of lymph nodes. Enlarged lymph nodes are often the first sign of lymphoma, a cancer of lymph cells. But all enlarged lymph nodes are not lymphoma.

Enlarged lymph nodes should not be ignored. However, since there are many noncancerous causes of lymph node enlargement, healthcare providers rarely go straight to a lymph node biopsy right away, when an enlarged node is detected. You should feel free to bring to your healthcare providers attention any odd lumps or bumps—and many common bumps turn out not to be lymph nodes at all.

If you do have palpable lymph nodes, your healthcare provider is trained to track down the most likely reasons first. Upper respiratory infections, for instance, are among the most common causes of swollen lymph nodes, such as those that might be palpated in the neck. Even when the reason for an enlarged lymph node is not immediately obvious to the healthcare provider, it is not uncommon to wait and see if the swelling goes away on its own, after a brief period, before investigating further. However, a persistently enlarged node needs to be evaluated.

What Kinds of Things Cause Swollen Lymph Nodes?

Here is an old memory device that some healthcare providers may still recall. Hodgkin lymphoma is just one possibility, but it serves as the skeleton for this mnemonic. It doesn't cover everything, but it is useful for thinking about diseases associated with lymphadenopathy, or swollen lymph nodes. Generalized lymphadenopathy means there are more than two nodes involved from different areas. As you can see, there are many possible causes:

H. Hematologic: Hodgkin disease, leukemia, and non-Hodgkin lymphoma

O. Oncologic: Metastasis to lymph node, malignant melanoma

D. Dermatopathic lymphadenitis: swollen lymph nodes that drain a patch of skin that has been disrupted or irritated

G. Gaucher’s disease: a rare genetic disease

K. Kawasaki’s disease: a rare autoimmune disease involving the blood vessels and inflammation

I. Infections: bacterial, viral, and parasitic

N. Niemann–pick disease: a genetic disease that involves metabolism

S. Serum sickness: an immune response to certain medications or treatments

D. Drug reaction: response to certain drugs

I. Immunological disease: for example, rheumatoid arthritis and lupus

S. Sarcoidosis: an inflammatory disease that can affect different parts of the body

E. Endocrine: hyperthyroidism

A. Angioimmunoblastic lymphadenopathy: this is an old term; currently considered a lymphoma.

S. Systemic lupus erythematosus (lupus, or SLE)

E. Eosinophilic granulomatosis: a systemic disease involving allergic and inflammatory manifestations

3 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Cheson BD, Fisher RI, Barrington SF et al. Recommendations for initial evaluation, staging and response assessment of Hodgkin and non-Hodgkin lymphoma: the Lugano Classification. J Clin Oncol. 2014;32(27)3059-3068. doi:10.1200/JCO.2013.54.8800

  2. Barrington SF, Mikhaeel NG, Kostakoglu L, et al. Role of imaging in the staging and response assessment of lymphoma: consensus of the International Conference on Malignant Lymphomas Imaging Working GroupJ Clin Oncol. 2014;32(27):3048-358. doi:10.1200/JCO.2013.53.5229

  3. Mohseni S, Shojaiefard A, Khorgami Z, Alinejad S, Ghorbani A, Ghafouri A. Peripheral lymphadenopathy: approach and diagnostic tools. Iran J Med Sci. 2014;39(2 Suppl):158-70.

By Indranil Mallick, MD
 Indranil Mallick, MD, DNB, is a radiation oncologist with a special interest in lymphoma.