Why does head and neck cancer cause swollen lymph nodes?

Lymph nodes are small immune structures positioned along drainage routes from the mouth, throat, nose, ears, and skin of the head and neck. A cancer in one of these areas may enter lymphatic channels and reach a nearby node. The node may enlarge as cells settle there. Inflammation around a tumour can also alter the node and make it easier to feel.

Swollen lymph nodes are not specific to cancer. Viral or bacterial infections, dental problems, and other inflammatory conditions can cause the same finding. A clinician considers the node’s location, tenderness, texture, mobility, and duration alongside symptoms such as a persistent mouth sore, hoarseness, swallowing difficulty, or ear pain. Further tests are chosen from that overall picture.

Arrange an assessment when a node persists, grows, feels hard or fixed, or appears without a clear short-lived infection. Write down when it started and whether you have fever, night sweats, dental symptoms, voice changes, or swallowing problems. Avoid repeatedly pressing the area. The clinician may examine the mouth and throat, feel other drainage areas, and recommend imaging or a needle sample when useful.

Get urgent help for breathing difficulty, inability to swallow saliva or fluids, rapidly expanding neck swelling, severe infection symptoms, or bleeding. Contact a clinician promptly for a node with progressive pain, skin redness, marked weakness, or new neurological symptoms. Do not wait for routine review if breathing or swallowing is becoming unsafe.

Ask which lymph-node region is involved, whether an infection could explain the finding, and what test would distinguish inflammation from other causes. Ask how to monitor the node, which symptoms require urgent contact, and when follow-up should occur.