What are lymph nodes?
Lymph nodes are small, bean-shaped organs located along the lymphatic vessels. They contain immune cells and act as filters where foreign substances, microorganisms and cell debris can be captured.
Most lymph nodes are not felt when they are normal. When infected or inflamed, they can become enlarged and tender. The neck, armpits, and groin are common places where you can feel them.
Read more about enlarged lymph nodes when you want to understand common causes and when investigation may be needed.
How does the lymphatic system work?
The lymphatic system collects fluid that has left the blood vessels and transports it back into the bloodstream. It also absorbs fat from the intestines and is an important part of the immune system.
Lymph nodes are located in groups. A gland in the neck often responds to an infection in the mouth, throat, or respiratory tract, while glands in the groin may respond to problems in the legs or abdomen.
Because glands reflect what is happening in their catchment area, the location can provide clues, but it is not enough alone to determine the cause.
Why do lymph nodes become swollen?
The most common cause is infection. Viral infections can cause multiple swollen glands and a general feeling of malaise, while a localized bacterial infection can cause a more pronounced, tender gland near the infection.
Inflammatory and autoimmune diseases can also affect lymph nodes. Less commonly, the swelling is due to a blood disease or cancer. Therefore, the entire symptom picture and not just the size of the gland are assessed.
Hard, non-tender or fixed glands, glands above the collarbone, and glands that continue to grow usually warrant more urgent assessment.
When should swollen lymph nodes be evaluated?
Contact your healthcare provider if a gland does not shrink after an infection has cleared, if it grows, feels hard, or is stuck to the surface. The same applies if you find a new lump without a clear explanation.
Assessment is especially important if the swelling is combined with prolonged fever, heavy night sweats, unexplained weight loss, pronounced fatigue, itching, or recurrent infections.
Seek medical attention more quickly if you have difficulty breathing or swallowing, rapidly increasing swelling of the throat, or severe general discomfort.
A lymph node or other lump that grows, feels hard, is stuck, or does not go away should be assessed by healthcare professionals.
How are enlarged lymph nodes investigated?
The doctor asks about infections, medications, travel, weight loss, fever, and other symptoms. The glands are assessed for location, size, tenderness, consistency, and mobility.
Blood tests can provide information about infection, inflammation, and blood counts. Ultrasound is often used for superficial glands and can help decide if sampling is needed.
Fine needle aspiration, core needle biopsy, or surgical tissue sampling may be needed when the cause is unclear. Tissue analysis is important because imaging alone cannot always determine why a gland is enlarged.
What role does diagnostic imaging play?
Ultrasound is often the first-line method for a superficial nodule because the examination can distinguish between fluid-filled and solid changes and show the shape and blood flow of the gland.
CT or MRI can be used to map deeper lymph nodes in the chest, abdomen, or pelvis and to assess nearby organs. The choice is guided by symptoms, clinical findings, and the medical question.
A full body examination does not replace clinical assessment or tissue sampling. When a specific gland is suspected, targeted investigation is often most important.
What happens after the initial assessment?
If a lymph node is considered reactive after an ongoing infection, healthcare providers may recommend that it be monitored for a limited period of time. The important thing is that it decreases when the infection is over and that no new warning symptoms appear. The follow-up should be clear so that a persistent change is not left without assessment.
Ultrasound assesses the shape, boundaries and internal structure of the gland, among other things. These characteristics can increase or decrease suspicion but do not always provide a certain diagnosis. If the image or symptoms are abnormal, sampling may be necessary even if the gland is not very large.
A tissue sample is analyzed by a pathologist. Sometimes a needle sample is sufficient, while other issues require the removal of an entire or larger portion of the gland. The choice depends on the disease you are trying to confirm or rule out.
It is rarely helpful to check the gland many times each day, as repeated touching can make the area tender and create more concern. Instead, follow an agreed-upon plan and seek treatment sooner if it is growing rapidly or if new general symptoms develop.