The short answer
Swollen lymph nodes are usually a sign the immune system is fighting an infection, and painful nodes are generally a sign of infection. A node is more worth checking when it is painless, hard or fixed in place, keeps growing, or does not get smaller after several weeks.
Swollen lymph nodes are usually caused by infections, not cancer.
They often appear with infections such as ear or skin infections. Soreness usually fades in days, but the node may take several weeks to shrink.
A node that is painless, hard, fixed, or growing is more worth checking.
Nodes that do not shrink after several weeks deserve a doctor's look.
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This page is for anyone who has found a swollen lump in the neck, underarm, or groin and is worried it could be cancer. It explains the usual causes, the signs that need a closer look, and when to get help fast.
The short answer
Usually not. Lymph nodes are small, bean-shaped glands found in your neck, underarms, groin, and elsewhere. They are part of your immune system. They swell up all the time, almost always from infection.
When you fight off a cold or a cut gets infected, nearby nodes can swell as they do their job. Cancer, including lymphoma, is a less common cause. But a node that lasts, keeps growing, or comes with other symptoms is worth checking.
What points toward infection
A node that swells up alongside an infection, such as an ear or skin infection, may be reacting to that problem. These nodes are often tender to the touch. MedlinePlus says the soreness usually goes away in a couple of days, though the node may take several weeks to return to normal size.
What points toward something that needs a closer look
Some nodes behave differently from the ones that come with an infection. The National Cancer Institute lists painless, swollen lymph nodes in the neck, underarm, or groin as a symptom of Hodgkin lymphoma. Hodgkin lymphoma is a cancer of the lymph system. A node that is painless is actually a clue worth paying attention to, since infected nodes are usually sore.
Other features that raise concern are:
- a node that keeps growing
- a node that does not get smaller after several weeks
- a node that feels hard, irregular, or fixed in place
- a node that shows up with no obvious infection nearby
Lymphoma can also come with fever, drenching night sweats, and weight loss you did not try to lose. Doctors call this group of symptoms "B symptoms."
Other causes besides infection and cancer
Infection and cancer are not the only possibilities. Some medicines cause lymph nodes to swell as a side effect. Autoimmune conditions, where the immune system is overactive, can cause widespread swollen nodes. Tooth problems, such as an impacted tooth, can also swell nearby nodes. MedlinePlus lists these among the other causes.
What a doctor checks next
Your doctor examines the node's size, texture, and location. They check whether it moves freely under your skin or feels fixed in place. They ask how long it has been there and whether you have had a recent infection nearby. Blood tests, including a complete blood count, are common first steps.
The node may stay enlarged for more than a few weeks with no clear cause, or other features may raise concern. If so, your doctor may order imaging, such as an ultrasound, or recommend a biopsy. A biopsy removes part or all of the node to look at under a microscope.
What watching and waiting looks like
If an infection seems like the likely cause, your doctor may choose to watch the node for a while before ordering a biopsy. Ask how long and what should bring you back sooner. If the node has not gone down after several weeks, or it has grown, contact your doctor.
When to get help sooner
Some signs need help sooner than a routine visit. Here is how fast to act.
- Call 911 or go to an emergency department if a swollen node in the neck comes with trouble breathing, noisy breathing, or trouble swallowing your own saliva. Do the same if your face or neck puffs up with breathlessness. Do the same if the skin over a node turns red and spreading while you feel feverish and confused. Do not drive yourself.
- Call your care team right away if a node swells quickly over just a few days, or the node is red and tender. Also call right away if a swollen node arrives with drenching night sweats, weight loss you did not try for, or a fever that keeps returning. For emergencies, call 911 or go to the ER.
- Call your care team if a node has not gotten smaller after several weeks or keeps growing. Also call if it feels hard, irregular, or fixed in place rather than moving under your fingers. MedlinePlus says to contact your provider for these.
What to ask your doctor
- Could this swollen node be from an infection, or does it need further testing?
- How long should we watch it before ordering a biopsy?
- Should my other lymph nodes be checked too?
- What symptoms should bring me back sooner?
Sources
Common questions
Does a swollen lymph node mean cancer?
Usually not. MedlinePlus says infections are the most common cause of swollen lymph nodes. Cancer can also cause them, so a node that does not shrink after several weeks or keeps growing needs a doctor's look.
Which nodes are more concerning?
MedlinePlus says to contact your provider if a node does not get smaller after several weeks, keeps getting larger, is red and tender, or feels hard, irregular, or fixed in place. Also contact your provider for fever, night sweats, or unexplained weight loss.
Are painful nodes better or worse?
MedlinePlus says painful nodes are generally a sign your body is fighting an infection, and slow, painless swelling may be due to cancer. Any node that lasts or grows deserves a look.
How long should a swollen node last?
The soreness of an infected node usually goes away in a couple of days. The node may not return to normal size for several weeks. NCI says symptoms that do not get better after a few weeks are worth a doctor's visit.
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Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes, and this is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
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