What should you know about a pea-sized lump at the back of the neck?

The back of the neck contains skin, muscles, and lymph nodes. A lump may follow a nearby scalp or skin irritation, infection, cyst, or another benign change. A lymph node can enlarge while the immune system responds to infection. Lymphoma, head and neck cancer, thyroid cancer, or cancer of unknown primary can also present with a neck lump, but a lump by itself cannot identify its cause. Explore [Lymphoma](/conditions/lymphoma/), [Head and Neck Cancer](/conditions/head-and-neck-cancer/), or [Thyroid Cancer](/conditions/thyroid-cancer/) for related information.

Useful details include when it appeared, whether it is growing, whether it moves under the skin, and whether the skin is red or tender. Note fever, night sweats, unexplained weight change, scalp changes, sore throat, voice change, or swallowing problems.

Book a primary-care or specialist appointment if the lump remains, becomes larger, feels firm or fixed, or has no clear connection with a recent illness. The clinician may inspect the skin and mouth, feel the neck, examine nearby areas, and decide whether imaging or a needle sample is needed. Do not squeeze, repeatedly press, or try to drain it.

Take a simple note of its approximate size and location rather than checking it constantly. If testing suggests a thyroid-related cause, [Thyroid Removal Surgery](/treatments/surgical-oncology/thyroidectomy/) is one treatment page your clinician may discuss only when appropriate.

Seek urgent medical help for difficulty breathing, inability to swallow, rapidly increasing swelling, severe pain, or spreading redness with fever. Arrange prompt assessment for a persistent lump, a hard or immobile lump, or a lump accompanied by persistent hoarseness, night sweats, or unexplained weight change. These features do not diagnose cancer, but they should not be ignored.

Ask what structure the lump seems to involve, whether a nearby infection or skin problem could explain it, how long observation is reasonable, and what change should prompt a return visit. Ask whether you need an ultrasound, blood tests, or a needle sample, and when you should expect the findings.