Swollen Lymph Nodes: When to Worry and When It Is Completely Normal

You are washing your face or rubbing your neck and you feel it—a tender, swollen lump under the skin. Your first thought might be alarming, but swollen lymph nodes are one of the most common physical findings in medicine. The human body contains approximately 600 lymph nodes, and at any given time, several of them may be palpable, particularly in the neck, armpits, and groin. In the vast majority of cases, swollen lymph nodes are a sign that your immune system is doing exactly what it should: fighting off an infection.¹

That said, there are situations where swollen lymph nodes warrant further investigation. This article explains what lymph nodes do, the most common reasons they swell, the specific characteristics that distinguish benign from concerning enlargement, and when to contact a healthcare provider.

What Are Lymph Nodes and What Do They Do?

Lymph nodes are small, bean-shaped structures distributed throughout the body along the lymphatic system. They function as filtration stations for lymph fluid, trapping bacteria, viruses, abnormal cells, and other foreign material. Inside each lymph node, immune cells—particularly lymphocytes and macrophages—analyze and respond to these threats. When the immune system mounts a response, lymph nodes can enlarge as immune cells proliferate. This is called reactive lymphadenopathy, and it is a normal, healthy process.

The lymph nodes you are most likely to notice are in the neck (cervical), under the jaw (submandibular), behind the ears (posterior auricular), in the armpits (axillary), and in the groin (inguinal). Children, in particular, frequently have palpable lymph nodes because their immune systems are actively learning to respond to new pathogens.

Common Causes of Swollen Lymph Nodes

1. Upper Respiratory Infections

The most common cause of swollen cervical lymph nodes is a viral upper respiratory infection—the common cold, influenza, or pharyngitis. When your throat or sinuses are infected, the cervical lymph nodes swell as they filter the infection. These nodes are typically tender to the touch, soft, mobile, and less than 1.5 centimeters in diameter. They usually resolve within two to four weeks after the infection clears.²

2. Dental and Oral Infections

Tooth abscesses, gingivitis, and peritonsillar abscesses can cause submandibular and cervical lymph node enlargement. The nodes are often tender and unilateral (on the same side as the infected tooth). Dental infections are sometimes overlooked as a cause of lymphadenopathy, so a dental examination may be warranted if no other source is identified.

3. Skin Infections and Wounds

Localized skin infections, including cellulitis, infected cuts, and insect bites, can trigger enlargement of the regional lymph nodes that drain that area. For example, an infected wound on the hand may cause axillary (armpit) lymph node swelling, while a foot infection may enlarge inguinal (groin) nodes.

4. Mononucleosis and Other Viral Infections

Epstein-Barr virus (the cause of mononucleosis) commonly produces widespread lymphadenopathy, particularly in adolescents and young adults. Other viral infections that can cause diffuse lymph node swelling include cytomegalovirus (CMV), HIV (especially during acute seroconversion), and certain vaccine-related reactions. Generalized lymphadenopathy—meaning swelling in two or more non-contiguous regions—often points to a systemic process rather than a localized infection.³

5. Autoimmune Conditions

Systemic lupus erythematosus (SLE), rheumatoid arthritis, and sarcoidosis can all cause lymph node enlargement as the immune system becomes chronically activated. In these conditions, lymphadenopathy tends to be diffuse and accompanied by other systemic symptoms such as joint pain, fatigue, skin rashes, or unexplained fevers. If autoimmune disease is suspected, further blood work including ANA, ESR, CRP, and specific antibody panels may be indicated.

6. Medication Reactions

Certain medications can trigger lymph node enlargement as a side effect. Phenytoin (used for seizures), allopurinol (used for gout), and some antibiotics are known to cause drug-induced lymphadenopathy. If swollen lymph nodes appeared shortly after starting a new medication, this temporal relationship is an important clinical clue.

Red Flags: When Swollen Lymph Nodes Need Urgent Evaluation

While most lymphadenopathy is benign and self-limited, certain characteristics raise the index of suspicion for serious conditions such as lymphoma, metastatic cancer, or severe infection. See a provider if you notice any of the following:

• Size greater than 2 centimeters (roughly the size of a large grape or greater)
• Firm, hard, or rubbery texture—as opposed to soft and tender
• Fixed or matted nodes—ones that do not move freely when pressed
• Painless enlargement that persists or grows over weeks
• Supraclavicular lymph nodes—nodes above the collarbone are always considered concerning and require prompt evaluation⁴
• Associated symptoms: unexplained weight loss (more than 10 percent of body weight over six months), drenching night sweats, persistent fevers without infection, or severe fatigue
• Generalized lymphadenopathy without an obvious infectious cause
• Duration greater than four weeks without improvement

These findings do not guarantee a serious diagnosis, but they do warrant a structured workup that may include blood tests, imaging, and potentially a biopsy.

How Are Swollen Lymph Nodes Evaluated?

The evaluation begins with a thorough history: when the swelling started, whether it is painful, any associated symptoms, recent infections or travel, medications, and family history. Physical examination assesses the size, texture, mobility, tenderness, and distribution of the enlarged nodes.

Initial lab work may include a complete blood count with differential, comprehensive metabolic panel, ESR/CRP (markers of inflammation), lactate dehydrogenase (LDH), and infectious disease testing as guided by history. Imaging—typically an ultrasound of the affected area—can characterize the node architecture and help distinguish reactive nodes from those with suspicious features. If imaging or clinical presentation raises concern, the next step is often a biopsy, either by fine-needle aspiration or excisional biopsy, to examine the tissue under a microscope.⁵

Telehealth is well-suited for the initial assessment. Your provider can review your symptom timeline, order labs and imaging at a local facility, and triage the urgency of further workup. If an in-person examination or biopsy is needed, they will coordinate the referral.

What You Can Do at Home

If your swollen lymph nodes are tender and associated with a clear infection (such as a cold or sore throat), the following measures can provide comfort while your body fights the infection:

• Warm compresses: Apply a warm, damp cloth to the swollen area for 15 to 20 minutes several times daily to ease discomfort.
• Over-the-counter pain relief: Acetaminophen or ibuprofen can reduce pain and inflammation. Follow the dosing instructions on the package.
• Rest and hydration: Adequate sleep and fluid intake support your immune system's ability to clear the infection.
• Monitor for changes: Note the size, tenderness, and duration of the swelling. If the node continues to grow, becomes hard, or fails to resolve within four weeks, contact a provider.

Swollen Lymph Nodes in Children

Palpable lymph nodes are extremely common in children and are usually benign. Children's immune systems encounter pathogens for the first time regularly, producing frequent reactive lymphadenopathy. Small, soft, mobile nodes in the neck or groin of an otherwise well child are rarely cause for concern. However, the same red flags that apply to adults—large, firm, fixed, painless, or supraclavicular nodes—also warrant evaluation in children, as do nodes accompanied by persistent fever, weight loss, or unexplained bruising.⁶

The Bottom Line

Swollen lymph nodes are a normal part of immune function and are almost always triggered by common infections. The key to knowing whether to worry lies in the specific characteristics of the node and the clinical context. Tender, soft, mobile nodes that appear during an infection and resolve within a few weeks are overwhelmingly benign. Hard, painless, fixed, or persistently enlarging nodes—especially in specific locations like the supraclavicular area—merit medical evaluation. A telehealth visit can help you sort through the possibilities, get appropriate testing ordered, and provide peace of mind.

Frequently Asked Questions