Swollen lymph nodes usually appear as small, oval-shaped bumps under the skin, typically 1 to 2 centimeters across (roughly the size of a kidney bean to a grape). They’re most noticeable in your neck, under your jaw, in your armpits, and in your groin, where clusters of nodes sit close enough to the surface to see or feel when they enlarge. In most cases, the swelling is your immune system responding to a nearby infection and will resolve on its own.
Where You’ll Notice Them
You have hundreds of lymph nodes throughout your body, but only a handful of clusters are close enough to the skin’s surface to become visible or palpable when swollen. The most common spots are along the sides of your neck (often triggered by a sore throat or cold), just below your jawline, behind your ears, in your armpits, and in your groin. Deeper nodes in your chest and abdomen can swell too, but you won’t see or feel those yourself.
A swollen node in the front of your neck during a bout of strep throat is one of the most familiar examples. If you notice a lump near your elbow or above your collarbone, those locations are less commonly affected by routine infections and deserve a closer look from a doctor.
What They Look and Feel Like
When a lymph node swells from a common infection, it typically feels like a smooth, somewhat rubbery bump that shifts slightly when you press on it. The skin over it may look normal, or it may appear red and inflamed. The node itself is often tender or sore to the touch, which is actually a reassuring sign. Tenderness generally points to an active immune response rather than something more serious.
Nodes that swell quickly over days to a couple of weeks and feel painful are almost always reacting to a nearby infection: a cold, an ear infection, a skin wound, or a dental issue. They tend to feel soft and mobile under your fingers, and they usually shrink back down once the infection clears.
Normal Size vs. Concerning Size
Doctors generally consider a lymph node abnormal when it exceeds 1 centimeter in diameter, roughly the width of a pencil eraser. But context matters. Groin nodes can be up to 1.5 centimeters and still be perfectly normal, since your legs and feet encounter minor infections and irritation constantly. These small, firm, painless groin nodes (sometimes called “shotty” nodes) are common and benign.
Size becomes more significant as it increases. In one study, no patient with a node smaller than 1 centimeter had cancer, while 8 percent of those with nodes between 1 and 1.5 centimeters did. That number jumped to 38 percent for nodes larger than 1.5 centimeters across. A node that keeps growing over weeks without an obvious cause, particularly past 2 centimeters, warrants medical evaluation.
Swollen Nodes in Children
Children’s lymph nodes are naturally more active and larger than adults’. It’s common to feel small, palpable nodes in kids between ages 3 and 5, and lymph nodes reach their peak size around ages 8 to 12 before shrinking after adolescence. In children, a neck node up to 2 centimeters, an armpit node up to 1 centimeter, and a groin node up to 1.5 centimeters are all considered within the normal range.
The vast majority of swollen nodes in children come from viral upper respiratory infections or bacterial infections like strep. Nodes larger than 3 centimeters in children have been associated with more serious conditions, including certain cancers and granulomatous diseases like cat-scratch disease.
How to Tell Nodes From Other Lumps
Not every bump under the skin is a lymph node. Cysts, for example, tend to feel firmer and more round, and they usually stay fixed in place when you push on them. Swollen lymph nodes, by contrast, feel softer and rubbery and shift a bit under your fingers. Location helps too: lymph nodes cluster in predictable areas (neck, armpits, groin), while cysts and fatty lumps (lipomas) can appear almost anywhere. Timing is another clue. A lump that showed up alongside a sore throat or skin infection and feels tender is almost certainly a reactive lymph node.
Signs That Need Attention
Most swollen lymph nodes are harmless, but certain characteristics suggest something beyond a simple infection. Nodes that feel hard, irregular in shape, or rubbery rather than soft may be worth investigating. Nodes that seem stuck in place, either fixed to the skin above them or to deeper tissue underneath, are more concerning than freely movable ones. Painless swelling is a particularly important detail: while tenderness usually signals infection, a firm, painless node that persists for several weeks can be a feature of lymphoma or other cancers.
Lymphoma specifically tends to present as painless swelling in the neck, armpits, or groin that doesn’t resolve within a few weeks. Other accompanying symptoms include persistent fatigue, fevers above 103°F that last more than two days or keep returning, drenching night sweats that soak through your pajamas and sheets, and unexplained weight loss of 10 percent or more of your body weight over six months. Any combination of a persistent, painless node with these symptoms is worth bringing to a doctor promptly.
A single firm, painless node on one side of the neck that doesn’t go away also deserves evaluation, as it can occasionally point to a head or throat cancer that hasn’t caused other noticeable symptoms yet. The key pattern across all these red flags is the same: hard, fixed, painless, and persistent. That combination looks and feels distinctly different from the tender, mobile, soft nodes that pop up with your average cold.