Swollen Lymph Nodes? Why They Swell & Medically Approved Next Steps

Swollen lymph nodes are common and, in most cases, harmless. If you've ever felt a tender lump in your neck during a cold, you've likely experienced this yourself. Lymph nodes are small, bean-shaped glands that are part of your immune system. They help your body fight infections and filter out harmful substances.

While swollen lymph nodes are often a sign that your body is doing its job, sometimes they can signal something more serious. Understanding why lymph nodes swell — and what to do next — can help you respond calmly and appropriately.

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What Are Lymph Nodes?

Lymph nodes are small structures located throughout your body. You have hundreds of them, but you're most likely to notice them in areas such as:

• The neck
• Under the jaw
• Behind the ears
• Armpits
• Groin

They're connected by lymphatic vessels that carry a clear fluid called lymph. This fluid contains infection-fighting white blood cells. When your body detects bacteria, viruses, or other threats, lymph nodes can swell as they produce more immune cells to fight the infection.

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Why Do Lymph Nodes Swell?

Swollen lymph nodes (also called lymphadenopathy) usually happen for a reason. The most common causes include:

1. Infections (Most Common Cause)

This is by far the leading reason lymph nodes enlarge.

Viral infections:

• Common cold
• Flu
• COVID-19
• Mononucleosis

Bacterial infections:

• Strep throat
• Ear infections
• Skin infections
• Dental infections

Other infections:

• Tuberculosis
• Cat scratch disease

When an infection is nearby, the closest lymph nodes often swell. For example:

• A sore throat can cause swollen lymph nodes in the neck.
• A skin infection on the leg may cause swelling in the groin.

In these cases, lymph nodes are often:

• Tender
• Soft or rubbery
• Movable
• About the size of a pea or grape

They typically shrink back to normal within 2–4 weeks after the infection improves.

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2. Immune System Conditions

Certain autoimmune conditions can cause persistent or recurring lymph node swelling. Examples include:

• Rheumatoid arthritis
• Lupus

In these cases, the immune system is overactive, and lymph nodes may stay enlarged longer than usual.

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3. Cancer (Less Common, But Important)

While most swollen lymph nodes are not cancer, persistent or unusual swelling should not be ignored.

Cancers linked to swollen lymph nodes include:

• Lymphoma (cancer of the lymphatic system)
• Leukemia
• Cancers that spread (metastasize) from other areas

Cancer-related lymph nodes are more likely to be:

• Hard or firm
• Painless
• Fixed in place (not movable)
• Growing over time

They may also be accompanied by other symptoms such as:

• Unexplained weight loss
• Persistent fever
• Night sweats
• Fatigue

If you notice these signs, it's important to speak to a doctor promptly.

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When Should You Be Concerned?

Most swollen lymph nodes are harmless and resolve on their own. However, medical evaluation is recommended if:

• The lymph node is larger than about 1 inch (2.5 cm)
• It continues growing
• It lasts longer than 2–4 weeks
• It feels hard or fixed in place
• You have unexplained fever
• You experience night sweats
• You have unexplained weight loss
• You feel persistent fatigue
• You have difficulty swallowing or breathing

Swelling in certain areas, such as above the collarbone (supraclavicular lymph nodes), deserves prompt medical attention, as it can sometimes signal a more serious condition.

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What Happens at a Doctor's Visit?

If you see a healthcare provider about swollen lymph nodes, they will typically:

1. Ask about your symptoms

   • How long have they been swollen?
   • Have you had a recent infection?
   • Any fevers or weight loss?

2. Perform a physical exam

   • Check the size, texture, and tenderness of the lymph nodes
   • Examine nearby areas for signs of infection

3. Order tests if needed

   • Blood tests
   • Imaging (ultrasound or CT scan)
   • Biopsy (in rare cases)

Most of the time, no invasive testing is needed. Doctors often recommend monitoring the lymph nodes for a short period if the cause seems likely to be a mild infection.

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Can You Treat Swollen Lymph Nodes at Home?

If your swollen lymph nodes are due to a mild infection, you can try:

• Rest
• Staying hydrated
• Over-the-counter pain relievers (such as acetaminophen or ibuprofen, if safe for you)
• Warm compresses to reduce tenderness

Avoid squeezing or repeatedly pressing on the lymph nodes. This can increase irritation and swelling.

If symptoms worsen or don't improve, it's time to seek medical advice.

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Neck Lumps: What If You Feel One?

Swollen lymph nodes in the neck are very common, especially during respiratory infections. Still, it's understandable to worry when you feel a lump.

If you've noticed swelling in this area and want to understand what might be causing it, you can use Ubie's free AI-powered symptom checker for a lump in the neck to get personalized insights about potential causes and guidance on whether you should seek immediate care.

However, an online tool does not replace a medical evaluation. If you're unsure or concerned, speak to a healthcare professional.

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How Long Do Swollen Lymph Nodes Last?

The timeline depends on the cause:

• Viral infections: Often improve within 1–3 weeks
• Bacterial infections: Improve after appropriate antibiotics
• Reactive swelling: May take several weeks to fully return to normal
• Chronic conditions: May persist and require ongoing care

It's also common for lymph nodes to shrink but not return completely to their original size after an infection. Small, non-tender, stable lymph nodes can remain for years without being dangerous.

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Key Takeaways About Lymph Nodes

• Lymph nodes are part of your immune system and help fight infection.
• Swelling usually means your body is responding to illness.
• Most swollen lymph nodes are caused by minor infections.
• Persistent, hard, painless, or enlarging lymph nodes need medical evaluation.
• Additional symptoms like weight loss, night sweats, or prolonged fever increase concern.

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When to Speak to a Doctor Immediately

Seek urgent medical care if you experience:

• Difficulty breathing
• Trouble swallowing
• Rapidly enlarging swelling
• Severe pain
• High, persistent fever
• Signs of a serious infection

And always speak to a doctor if you are worried about something that could be serious or life-threatening. It's far better to get checked and be reassured than to ignore concerning symptoms.

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Final Thoughts

Swollen lymph nodes are usually a sign that your immune system is working as it should. In most cases, they are temporary and linked to common infections. Still, persistent or unusual swelling deserves attention.

Pay attention to how long the lymph nodes have been swollen, how they feel, and whether you have other symptoms. If something doesn't seem right, trust your instincts and speak to a healthcare professional.

Your health is too important to ignore — and early evaluation, when needed, makes all the difference.