What can swollen glands be a symptom of?

September 21, 2025 •

3 min read

Swollen glands, or lymph nodes, are a sign that your body is fighting an infection or illness, with viral infections being the most frequent cause. These small, bean-shaped structures are a critical part of your immune system, filtering lymph fluid and trapping germs. Knowing what can swollen glands be a symptom of is the first step toward understanding what might be happening inside your body.

Quick Summary

Swollen glands are a common indicator that your immune system is activated, most often due to viral or bacterial infections like colds, strep throat, or mono. Less commonly, they can be a sign of autoimmune disorders, certain medications, or, in rare cases, cancers like lymphoma. Their location, accompanying symptoms, and duration provide crucial clues to the underlying cause.

Key Points

Immune Response: Swollen glands, or lymph nodes, most often indicate that your immune system is fighting an infection, such as a cold or strep throat.
Infection Clues: The location of the swollen lymph nodes can suggest the site of the infection, like neck swelling for a throat infection or underarm swelling for an arm infection.
Duration Matters: While infection-related swelling typically subsides within 2-4 weeks, persistent or growing lymph nodes warrant medical attention.
Less Common Causes: Autoimmune disorders like lupus or rheumatoid arthritis, as well as certain medications, can also cause lymph node enlargement.
Cancer Indicators: In rare cases, hard, painless, or fixed lymph nodes that are accompanied by fever, night sweats, or unexplained weight loss may be signs of a more serious condition like lymphoma.
Seek Medical Advice: If swelling persists, worsens, or is accompanied by other concerning symptoms, it is essential to consult a healthcare provider for proper diagnosis and treatment.

Understanding the Lymphatic System

Your body's lymphatic system is a vital network of organs, vessels, and lymph nodes that play a central role in your immune defense. The lymph nodes act as filters, trapping and destroying bacteria, viruses, and other foreign invaders. When your body detects an infection, the lymph nodes nearest to the affected area will swell as they work overtime to fight off the illness.

Common Infectious Causes

Infections are, by far, the most frequent reason for enlarged lymph nodes. The location of the swelling often points to the source of the infection. Common causes include upper respiratory infections like colds or the flu, strep throat, mononucleosis, skin infections, and dental issues.

Less Common but Serious Infectious Causes

Less common infections such as Tuberculosis (TB), HIV, and Cat Scratch Fever can also lead to lymph node swelling.

Autoimmune and Inflammatory Conditions

Chronic conditions causing inflammation can also be a cause. These include Lupus, Rheumatoid Arthritis, and Sarcoidosis.

The Link Between Cancer and Swollen Glands

While rare compared to infections, certain cancers can cause swollen lymph nodes, a primary concern for some. Lymphoma and Leukemia, cancers of the lymphatic system or blood-forming tissues, can cause swelling. Cancer from elsewhere in the body can also spread to lymph nodes.

Comparing Causes of Swollen Glands


Characteristic	Typical Infection (e.g., Cold)	Serious Condition (e.g., Cancer)
Onset	Sudden, often with other flu-like symptoms.	Slow, gradual, and sometimes painless.
Sensation	Often tender and painful to the touch.	Typically painless, but can feel firm or hard.
Mobility	Usually mobile and can be moved under the skin.	Can feel fixed or stuck in place.
Duration	Resolves within 2-4 weeks as the infection clears.	Persists or continues to enlarge for more than 2-4 weeks.
Accompanying Symptoms	Fever, sore throat, cough.	Unexplained weight loss, night sweats, persistent fever.

When to Seek Medical Attention

Though most swollen glands clear up naturally, certain signs warrant medical consultation. See a doctor if swelling lasts over two to four weeks, the nodes are painless, hard, or fixed, or if accompanied by unexplained fever, night sweats, or significant weight loss. Swelling in multiple body areas or difficulty breathing/swallowing also requires prompt attention.

The Importance of Diagnosis and Treatment

Getting an accurate diagnosis is key to the right treatment. A doctor will evaluate your history and symptoms, possibly ordering tests like blood work, imaging, or a biopsy. Treatment targets the underlying cause; antibiotics for bacterial infections, and supportive care for viral ones. Autoimmune diseases or cancers require specific, tailored treatments.

Learn more about the crucial role of the lymphatic system in health and disease through this comprehensive resource: American Cancer Society's Guide to Lymph Nodes.

Conclusion

Swollen glands are a common indicator of your immune system working. Most often they signal an infection the body is fighting. However, recognize signs that might point to a more serious issue. Pay attention to how long the swelling lasts, the feel of the glands, and any other symptoms to know when to seek medical advice. Always consult a healthcare provider with concerns about persistent or unusual swelling.

Frequently Asked Questions

The most common cause of swollen glands (lymph nodes) is an infection, typically a viral one like the common cold or flu. Bacterial infections like strep throat are also a frequent culprit.

Stress does not directly cause swollen lymph nodes, but it can weaken your immune system, making you more susceptible to infections that can then cause swelling. Anxiety can also increase awareness of your body, making you notice otherwise normal lymph nodes.

You should see a doctor if your swollen glands persist for more than two to four weeks, are growing larger, feel hard or fixed, or are accompanied by fever, night sweats, or unexplained weight loss.

In rare cases, swollen glands can be a symptom of cancer, such as lymphoma or leukemia. Cancerous lymph nodes are often hard, painless, and don't move when pressed. This is far less common than infectious causes.

Lymph nodes are located throughout the body, but common areas where they can be felt include the neck, under the chin, in the armpits, and in the groin. The location can offer clues about the cause of the swelling.

Infection-related swelling is typically painful, tender, and mobile, resolving within a few weeks. Swelling from cancer is often painless, hard, fixed in place, and persistent or growing.

Yes, some vaccines can cause lymph nodes to swell as part of the body's normal immune response. This is usually a temporary side effect.

Treatment depends on the underlying cause. Viral infections often resolve on their own, while bacterial infections may require antibiotics. In more serious cases, addressing the underlying immune disorder or cancer is necessary.