When to Worry About Swollen Lymph Nodes

Here are the most concerning qualities to look for, according to doctors.

By Erica SloanMedically reviewed by Mathew Devine, DO

October 30, 2024

illustration of hexagons with circles denoting swollen lymph nodes

A swollen lymph node can be a bit like your body’s version of a red flag: When one of these bean-shaped clusters of immune cells in your neck, armpit, or groin puffs up, it’s typically an indication that something out of the ordinary is floating around in your system. And it can be pretty tough to un-feel it once you’ve detected its presence. But as with any early warning sign, it’s not always clear just how concerned you should be about a larger-than-normal lymph node. Is it something that’ll resolve itself if you let it lie—or should you address this potential omen straightaway?

It’s a tricky question to answer for a symptom that’s so common and can be related to everything from a minor infection to cancer—quite the range in severity. In general, a lymph node is a checkpoint along the route of your lymphatic system, a part of your immune system that’s responsible for catching and filtering out foreign substances that could cause harm. When it detects a rush of those invaders, it pumps out a bunch of white blood cells to squash the influx, Kisha Davis, MD, MPH, FAAFP, a member of the board of directors of the American Academy of Family Physicians, tells SELF. The surge in activity can make it grow larger, temporarily. So, often when a lymph node swells, “it means it’s doing what it’s supposed to do,” she says.

In plenty of cases, your lymph nodes are well-equipped to fight what ails you (for instance, a minor viral or bacterial illness) and will shrink back down once they do. But in other situations, the suspicious agent causing them to swell is a more serious infection, autoimmune condition, or even cancerous cells in your blood or a nearby organ. It’s the reason why “there tends to be a lot of over- and under-reaction to lymph nodes,” Dr. Davis says. For some people, it’s easy to jump to the worst possible conclusion, even if it’s rare; while for others, it’s far more tempting to brush it off—and neither approach is ideal.

To be sure, it’s never a bad idea to see a doctor for a lymph node that’s bigger than your norm. But learning more about the different reasons why these organs can balloon (and what factors point to a more dangerous cause) can help you avoid either doom-googling into oblivion or missing the kind of red flag that’s worth acting on ASAP.

Swollen lymph nodes can crop up when your body is fighting many different kinds of infection or illness.

First, a little anatomy lesson to clarify why lymph nodes are so prone to bulging. The lymphatic system is a complex network of organs, vessels, tissues, and fluid. Your lymph nodes exist in specific spots along lymphatic vessels, which basically run parallel to your blood vessels. And the two sets of tubes work in tandem: Your heart pumps blood into your arteries, and it travels all the way to your tiniest capillaries, where plasma (a.k.a. the liquid part) seeps through capillary walls to deliver oxygen and nutrients to cells. At a certain point, that accumulating fluid has to get back into your circulatory system, Larry Norton, MD, a board-certified medical oncologist at Memorial Sloan Kettering, in New York, tells SELF. A big portion of it returns via your veins, while the rest gets picked up by your lymphatic vessels, he explains. This liquid, now called lymph, flows through your nodes, which, again, act as filters, trapping suspicious components and deploying an army of white blood cells against them.

All that commotion in response to a threat is, again, what shows up as swelling. That can look different depending on the person, but generally, a lymph node bigger than one centimeter across is considered swollen, Sairah Ahmed, MD, an associate professor in the department of lymphoma at the University of Texas MD Anderson Cancer Center, tells SELF.

Anything abnormal in your lymph—whether that’s bacteria, a virus, or something else—is subject to that screening process and immune response, which is why a variety of illnesses can cause swollen lymph nodes. On the mild end, that includes everything from the common cold to strep throat to a localized skin infection from a cut. On the more severe side, it could be something like parasitic food poisoning, an STI, or yes, in rare instances, various types of cancer (it’s estimated that as few as 1.1% of swollen nodes are malignant). “Some people might feel the tingle of a swollen lymph node before they get sick, whereas in others, it can come after,” Dr. Davis says, “and it’s not uncommon for the swelling to outlast an infection.”

For similar reasons, an autoimmune condition like lupus or rheumatoid arthritis can also lead to aggravated lymph nodes; in these scenarios, your body is mistakenly deploying an immune defense against your own cells, which can surface in nodes throughout your body. You can also experience bulky glands after an immunization (within a few days and for up to a couple months), as has been reported with the COVID-19 vaccine. That just means your white blood cells are “doing as they ought to, ramping up antibody production to protect you from subsequent infection,” Dr. Norton says.

The puffy node’s location may hint at the origin of the issue, Dr. Ahmed says. With a respiratory illness, for instance, a palpable gland tends to be beneath your chin or in your neck; in the case of a breast infection or cancer, you might feel it in your armpit, she says. However, invading microbes and cancerous cells can also spread in your blood, enter your lymph, and be picked up by a node far from where you’re having symptoms, she adds, which then blows up in response. (Separately, lymphoma, or cancer of the lymphatic system, happens when the white blood cells in your lymph nodes themselves change in shape and multiply, which may also cause swelling.)

One last possibility: You’re on a particular medication for which swollen lymph nodes are a known side effect, Dr. Ahmed says. Some blood pressure meds (captopril, atenolol), as well as certain antibiotics (penicillin, trimethoprim), seizure treatments (carbamazepine, phenytoin) and drugs for arthritis (sulindac) and kidney stones (allopurinol) can cause that reaction, typically by blocking or slowing the typical flow of lymph.

Certain symptoms and coinciding factors can make a swollen lymph node more worrisome.

It bears repeating that any big node that concerns you is reason enough to pay a visit to your doctor. But in the meantime, your recent health history can help you determine, at a topline level, what might be at the root of an enlarged gland (and when to worry about swollen lymph nodes).

For example, you may be able to attribute a swollen lymph node to a recent immunization if you’ve been vaccinated in the past few weeks or a medication if you just started a new one; or infection may be more clearly to blame if you’ve recently cut or burned your skin, or gotten a manicure, Dr. Norton says. Similarly, a puffy neck gland is likely tied to a respiratory illness if you also have symptoms of a virus (like a cough or sore throat).

A general rule is to give a node about two to three weeks to settle down, Dr. Ahmed says, after which point if it hasn’t shrunk, you should see a primary care doctor. They can inspect it, assess your history, and either offer treatment (say, an antibiotic or antifungal for an infection) or order testing to get to the bottom of a mysterious one (more on that below).

At the same time, there are a few characteristics that Dr. Ahmed says tend to make physicians more suspicious of cancer and warrant a call to your doctor ASAP—namely, if a node is enlarged and:

Feels especially firm or hard
Is fixed in place or doesn’t move when you touch it
Is draining pus
Is consistently growing in size

Another time to worry about swollen lymph nodes? You notice a few in more than one spot—for instance, around your neck and collarbone and in your armpits or groin.

Certain other co-occurring symptoms should ring alarm bells too, Dr. Ahmed says. “If you have palpable lymph nodes plus fevers or night sweats—where you’re having to get up and change the bedsheets—or you’ve lost more than 10% of your body weight, that’s reason to see your doctor sooner,” she says, given these can be signs of lymphoma. Intense fatigue (the kind that doesn’t let up even after a full night of sleep) should also trigger a doctor’s visit for the same reason, while experiencing difficulty breathing or swallowing warrants immediate medical care, she adds.

Here are a few things to expect if you get checked out for a swollen lymph node.

Likely the first thing that a primary care clinician or urgent care doctor will do is ask you a bunch of questions about your recent health history, so it’s a good idea to have pertinent info fresh in your mind or even written down, Dr. Norton says. That includes any recent illnesses or immunizations, changes in medications, other symptoms you’ve been experiencing, and anything else out of the ordinary in your life, he says (for instance, international travel, scratches from an animal, tick bites, and the like). All of these details can help the provider more quickly suss out the genesis of your puffy node.

From there, your doctor may examine the node with their hands, Dr. Ahmed says. If they suspect you have a particular infection (like a sinus infection or an STI, for example), they might then order testing and prescribe treatment accordingly. But in other cases, they might conclude that your node is likely the result of a minor illness that your body will fight off and suggest you simply monitor it for a few weeks. It’s important, in that scenario, to keep an eye out for any changes and remember to loop back at the timeframe they’ve recommended if it’s still swollen—ideally with the same physician, who’s now aware of your history.

In the meantime, if the node is painful or just bugging you, resist the urge to touch or squeeze it, Dr. Norton says, which can make the swelling worse. (He often tells patients to slap a Band-Aid over a node as a tactile reminder to keep their fingers off it.) To address discomfort, both Dr. Davis and Dr. Ahmed suggest applying a warm compress and taking an over-the-counter anti-inflammatory medication like ibuprofen. One last tip from Dr. Davis: Drink plenty of water to give your immune system a hand in potentially flushing out an invader.

If, by contrast, your initial history and evaluation reads as more concerning to your provider, or your gland remains super puffed-up after the wait-and-see period you’re given, then your doctor will do some additional testing. That could include blood work to measure your white and red blood cell counts and potentially to look for substances that can signify cancer, as well as imaging (for instance, an ultrasound, CT scan, or PET scan) to check out what’s going on inside your lymph node(s). If that’s not definitive, then you may ultimately need to get a biopsy, which involves either removing the lymph node in its entirety or just “sticking a needle into it to pull out some cells,” Dr. Norton explains. Should a closer look under a microscope reveal anything that could be cancerous, your doctor will then refer you to an oncologist.

But again, the likelihood of an oversized gland being cancer is extremely low, and especially so if it doesn’t meet any of the worrisome criteria above, and you don’t have any of the other noted cancer symptoms. Regardless, if a swollen node is really bugging you or has been lingering, it’s always a better idea to see a doctor than it is to let it fester, Dr. Norton says. Chances are, you’ll get care or helpful reassurance—and in uncommon cases, you’ll increase your odds of solving a more serious issue beneath the surface.