Swollen lymph nodes usually feel like small, round bumps under your skin that are tender to the touch, often about the size of a pea or larger. You’ll most commonly notice them along the sides of your neck, under your jaw, in your armpits, or in your groin. In most cases, they swell because your immune system is actively fighting off an infection nearby, and they return to normal within a couple of weeks.
Where to Check for Swollen Lymph Nodes
You have hundreds of lymph nodes throughout your body, but only a handful of clusters sit close enough to the surface of your skin to feel with your fingers. The areas where you’re most likely to notice swelling are:
- Neck and jaw: along the sides of your neck, under your jawline, behind your ears, and at the base of your skull
- Above your collarbone: in the small hollow just above each collarbone
- Armpits: deep in the center of each armpit
- Groin: in the crease where your leg meets your torso
Some lymph nodes sit deeper inside your chest and abdomen, where you can’t feel them at all. Those only show up on imaging like a CT scan or ultrasound. When people talk about “checking for swollen lymph nodes,” they’re almost always referring to the superficial clusters listed above.
How to Feel for Them
Use the pads of your index and middle fingers, not your fingertips. Press gently in small circular motions over each area, rolling the skin over the tissue underneath. You’re feeling for anything that seems like a soft bump or marble just beneath the surface. Start on one side, then check the same spot on the other side. Clinically significant swelling is almost always asymmetric, meaning one side is noticeably larger than the other. If both sides of your neck feel the same, that’s reassuring.
A few things can fool you. The salivary glands under your jaw can feel like lumps, especially if you press firmly. On your neck, you might feel the pulse of your carotid artery and mistake it for a node. If the bump you’re feeling pulses with your heartbeat, it’s your artery, not a lymph node.
What Normal Versus Swollen Feels Like
Healthy lymph nodes are tiny, usually less than one centimeter across, and most people can’t feel them at all. Small, soft, mobile nodes in the groin or under the jaw can be normal even when you can feel them, especially in thinner people. A node becomes worth paying attention to when it’s noticeably bigger than a pea, feels firm or hard, or appeared recently when you couldn’t feel anything there before.
Texture and movement matter. Nodes that are swollen from a common infection tend to be tender, somewhat soft, and they slide around easily under your fingers when you press on them. A node that feels hard, rubbery, or stuck in place (it doesn’t move when you push it) is less typical of a simple infection. That said, how a node feels can’t reliably confirm or rule out any specific cause on its own. It’s one piece of the picture, not the whole diagnosis.
What Causes Lymph Nodes to Swell
The most common reason, by far, is infection. Lymph nodes act as filtering stations for your immune system, trapping bacteria, viruses, and other threats. When your body is fighting something off, the nodes nearest the infection ramp up their activity and enlarge. A sore throat or cold often swells the nodes in your neck. A skin infection or cut on your hand might enlarge the nodes in your armpit. An ingrown hair or minor infection on your leg can trigger swelling in your groin.
Bacterial infections from strep and staph are among the most common culprits. Viral infections like the flu, mononucleosis, and even a standard upper respiratory infection frequently cause noticeable neck swelling. Less common infections, including cat scratch disease and tuberculosis, can also trigger it. Beyond infections, autoimmune conditions and certain cancers, particularly lymphoma, can cause lymph nodes to enlarge.
The location of the swelling often gives a clue. Nodes that swell in just one area usually point to a problem nearby: an ear infection causing swelling behind the ear, a dental infection causing swelling under the jaw. When nodes swell in multiple unrelated areas at the same time, that’s called generalized lymphadenopathy and typically suggests something systemic, like a widespread viral infection or, less commonly, something more serious.
Painful Versus Painless Swelling
Tenderness is actually somewhat reassuring. Painful or tender nodes most often indicate inflammation from an active infection. Your body is fighting something, and the soreness reflects that battle. This kind of swelling usually resolves as the infection clears.
Painless swelling can be trickier to interpret. A hard, painless node that doesn’t move freely under your fingers raises more concern for something like a malignancy. But painless nodes can also simply be leftover from a past infection that your body resolved on its own. The key distinction is whether the node keeps growing, stays the same for weeks, or eventually shrinks back down.
Signs That Need Medical Attention
Most swollen lymph nodes resolve on their own within two weeks as the underlying infection clears. Any swelling that persists beyond two to four weeks without shrinking deserves a medical evaluation. Beyond duration, certain accompanying symptoms change the urgency:
- Unexplained weight loss
- Night sweats that soak your sheets
- Persistent or recurring fevers
- Fatigue that doesn’t improve with rest
- Nodes that keep getting bigger over time
If you have difficulty swallowing or breathing because of swollen nodes in your neck, that warrants immediate care rather than a wait-and-see approach.
Nodes above the collarbone (supraclavicular nodes) get extra attention from doctors because swelling in that specific location is more frequently associated with serious underlying conditions than swelling in the neck or groin.
What Happens During a Medical Evaluation
A doctor’s evaluation starts with a physical exam and a detailed conversation about your symptoms, how long the swelling has lasted, and whether you’ve had any recent illnesses, travel, or exposures. This basic clinical assessment is the single most important step in narrowing down the cause.
If the cause isn’t obvious from your history and exam, the next step is usually blood work to look for signs of infection or other abnormalities. Imaging typically starts with an ultrasound, which gives a detailed look at the node’s size, shape, and internal structure without any radiation. CT or MRI scans may follow if the doctor needs to see surrounding tissue or check for deeper nodes you can’t feel from the surface.
When imaging and blood work don’t provide a clear answer, a tissue sample may be needed. This can range from a needle biopsy, where a small sample of cells is drawn out through a thin needle, to a surgical biopsy that removes part or all of the node for examination under a microscope. A surgical biopsy provides the most definitive answer, especially when lymphoma is a possibility.