Enlarged Lymph Nodes: Why They Swell and When to See a Doctor

You wake up, instinctively touch your neck — and under your jaw you find a tender lump that wasn't there yesterday. A familiar story: this is how a lymph node behaves when it's doing its job. Below, calmly, about what this usually means, how long it lasts, and when to see a doctor.

What these nodes are and where to feel for them

Lymph nodes are found throughout the body and are part of the immune system. Together with the spleen, tonsils, and adenoids, they are organized centers of immune cells that filter antigens from extracellular fluid. The medical term for enlargement is lymphadenopathy.

With your fingers, you can usually feel nodes in the groin, under the arm, on the neck (a chain runs on both sides in front, on the sides, and along the back), under the jaw and chin, behind the ears, and at the back of the head. Size depends on age, location, and previous immunological events: in newborns, nodes are barely noticeable, their mass increases until age 8–12, and from adolescence onward, gradual atrophy begins.

So a small node you've felt is normal anatomy, not immediately a tumor.

Why a node swells

A node enlarges near an infection to help the body fight it. Infections are the most common cause: colds, flu and other acute respiratory viral infections, tonsillitis and throat inflammation, ear inflammation, infectious mononucleosis, including that caused by cytomegalovirus. There are also dental abscess or impacted tooth, gingivitis, mouth ulcers, skin infections, tuberculosis, sexually transmitted infections.

Less often, the cause is immune and autoimmune diseases (HIV, rheumatoid arthritis), a reaction after vaccination, certain medications. And very rarely — oncological diseases: leukemia, Hodgkin's and non-Hodgkin's lymphomas; a nearby node is often the first place cancer spreads to. Some cases remain without an identified cause and resolve on their own.

So thinking first about the rare is not the best strategy.

How a reactive node behaves

It feels like a painful, tender lump when pressed. Sometimes only one node on one side enlarges. Other symptoms may appear nearby: sore throat, cough, fever. Sudden painful enlargement is usually associated with trauma or infection, while slow and painless enlargement is more suspicious. By prevalence, regional (local) and generalized forms are distinguished, when nodes are symmetrically enlarged in two or more areas.

Tenderness when pressed is rather a good sign: it indicates that the immune response is working.

How long it lasts

Pain when pressed usually subsides within a few days. The node itself may not return to its usual size for several more weeks. Enlargement caused by infection usually resolves on its own within 1–2 weeks — the exact timeframe depends on the cause.

A week without reduction is already a sufficient benchmark to see a family doctor.

How a doctor evaluates a node

First — an examination and conversation: when the swelling appeared, whether it arose suddenly, whether it hurts when pressed. In adolescents, sexual history and possible intravenous drug use are clarified separately. Next — testing: a complete blood count with a leukocyte differential, liver and kidney function tests, node biopsy, chest X-ray and CT, abdominal CT.

If the enlargement lasts more than 3 weeks, the list is expanded: lactate dehydrogenase activity and uric acid level, serological testing for Bartonella henselae (the causative agent of cat-scratch disease), a tuberculosis skin test, and an interferon-gamma release assay. For an unusual picture, the patient is referred to a hematologist or oncologist.

The set of tests is individual each time: the fact that the doctor did not order everything at once is rather professionalism than negligence.

When to see a doctor

There are signs with which you don't wait two weeks:

• the node grows or does not shrink within a week
• it feels firm, uneven, and does not move
• the skin over it is red, the node is painful
• night sweats, high fever, unexplained weight loss
• a node above or below the collarbone

Call 103 or 112 immediately if, along with enlarged nodes, you have severe difficulty swallowing or breathing difficulties.

This text is for reference and does not replace a doctor's consultation — a diagnosis is made by a doctor after examination.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer