Lymphadenopathy (Swollen Lymph Nodes)

What lymph nodes do

Lymph nodes are small, bean-shaped filters spread throughout the body along lymph vessels, clustered in the neck, armpits, groin, chest and abdomen. They contain white blood cells that trap and fight germs and abnormal cells. When they are busy fighting an infection, they enlarge, which is why swelling is so common.

Normal nodes are usually less than 1 cm. In the groin, up to about 1.5 cm can be normal. Children often have easily felt neck nodes that are normal.

Localized vs generalized lymphadenopathy

Causes by location

Common and serious causes

Infections

• viral infections: colds, flu, COVID-19, mononucleosis, cytomegalovirus, HIV
• bacterial infections: strep throat, skin infections, dental abscesses, lymphadenitis (infection of the node itself)
• cat-scratch disease, tuberculosis, syphilis, toxoplasmosis

Immune and inflammatory conditions

• lupus, rheumatoid arthritis, sarcoidosis
• Kawasaki disease in children
• reactions to medicines, such as some anti-seizure drugs and allopurinol
• after vaccinations (especially armpit nodes after arm vaccines)

Cancers

• lymphoma, both Hodgkin and non-Hodgkin
• leukemia, especially chronic lymphocytic leukemia in older adults
• cancers that spread to lymph nodes, such as breast, lung, head and neck, skin and gut cancers

When to worry about swollen lymph nodes

Features that raise concern:

• size larger than about 2 cm
• hard, rubbery or fixed to surrounding tissue
• painless and growing
• persisting more than 4 to 6 weeks
• located above the collarbone
• generalized swelling without an obvious infection
• "B symptoms": unexplained fevers above 38 °C (100.4 °F), drenching night sweats, weight loss of more than 10 percent in 6 months
• age over 40, smoking history, or a history of cancer

Tenderness usually suggests inflammation or infection, but it does not rule out cancer.

Diagnosis

The doctor will ask about recent infections, travel, pets, sexual history, medicines, vaccinations and B symptoms, then examine all node areas, the throat, skin, liver and spleen.

Tests depend on the findings:

• Blood tests: complete blood count with smear, inflammatory markers, mono test, HIV test, and others such as syphilis, toxoplasma or TB tests
• Ultrasound: shows node size, shape and internal structure
• Chest X-ray or CT for chest or abdominal nodes
• Biopsy: needle biopsy or, preferably for suspected lymphoma, removal of the whole node (excisional biopsy)

A short period of observation, typically 2 to 4 weeks, is reasonable for a node that seems reactive to infection in a low-risk person. Steroids should not be given before a diagnosis, because they can mask lymphoma.

Treatment

Treatment targets the cause:

• Viral infections: rest, fluids and pain relief; the nodes shrink as the infection clears
• Bacterial infections: antibiotics; an abscessed node may need drainage
• TB: a multi-drug antibiotic course for 6 months or more
• Autoimmune conditions: treating the underlying disease
• Cancers: chemotherapy, radiation, immunotherapy or surgery depending on type

For tender nodes, warm compresses and acetaminophen (paracetamol) or ibuprofen at the label dose help. Do not give aspirin to children or teenagers.

Frequently asked questions

What is lymphadenopathy?

It is the medical term for lymph nodes that are enlarged or abnormal. Most often it is a normal response to infection, such as a cold or sore throat. It can also be caused by autoimmune diseases, medicines and, less commonly, cancers such as lymphoma.

When should I worry about a swollen lymph node?

See a doctor if a node is larger than about 2 cm, hard, fixed, painless or growing, lasts more than 2 to 4 weeks, is above the collarbone, or comes with fevers, night sweats, weight loss or unexplained bruising.

What is the difference between localized and generalized lymphadenopathy?

Localized lymphadenopathy affects nodes in one area and is usually caused by a nearby infection. Generalized lymphadenopathy affects two or more separate areas and suggests a body-wide condition such as mononucleosis, HIV, an autoimmune disease or lymphoma.

How long do swollen lymph nodes last?

Nodes swollen from a common infection usually shrink within 2 to 4 weeks, though they can stay slightly enlarged for longer. Nodes that keep growing or last more than 4 to 6 weeks should be checked by a doctor.

Can stress cause swollen lymph nodes?

Stress itself does not directly cause swollen lymph nodes, but it can make you more prone to infections that do. Persistent swelling should not be attributed to stress without a medical check.