Key takeaways: Lymph nodes are part of the immune system and often swell during colds, ear infections, and skin irritation. Small, soft, movable nodes are usually normal. A node that’s red, warm, tender, and growing may be infected. Nodes that are hard, fixed, very large, growing without infection, or come with fever, weight loss, or night sweats need evaluation.
Parents often feel small lumps on their baby’s neck, behind the ears, or at the back of the head. Most are normal lymph nodes.
What Lymph Nodes Do
Lymph nodes filter germs and help fight infection. They’re found throughout the body, including the neck, armpits, and groin.
Common Causes of Swelling
- Colds and other viral infections.
- Ear infections.
- Scalp irritation, such as cradle cap or eczema, can cause swollen nodes at the back of the head.
- Vaccines can cause temporary swelling near the injection site.
- Teething is sometimes blamed, but evidence for this is limited.
From the author
From First Breath to First Birthday is my month-by-month guide to your baby’s first year, written as a NICU and postpartum nurse. My book covers everyday newborn care month by month, plus the warning signs that mean it’s time to call the doctor.
Normal Lymph Nodes
- Small (less than about 1 cm, the size of a pea).
- Soft or rubbery.
- Movable under the skin.
- Not red or tender.
Nodes may stay slightly enlarged for weeks after an infection.
Lymphadenitis (Infected Node)
- Red, warm, tender, swollen node.
- Often with fever.
- Usually treated with antibiotics.
When to See a Doctor
- A node larger than about 2 cm.
- A node that’s hard, fixed in place, or growing.
- A node above the collarbone.
- Swelling that lasts more than 2 to 4 weeks without an obvious cause.
- Swelling with fever, poor feeding, weight loss, night sweats, or bruising.
- A red, warm, painful node.
Seek prompt care if your baby: has a swollen node with high fever, trouble swallowing or breathing, or seems very unwell.
The Bottom Line
Small, soft, movable lymph nodes are usually a normal response to infection. Nodes that are large, hard, growing, or come with other symptoms need a check.
Want more support for your baby’s first year? My book, From First Breath to First Birthday, is available on Amazon.
Related Articles
- Kawasaki Disease: Signs Parents Should Know
- Ear Infections: Signs, Treatment, and Watchful Waiting
- Rashes With Fever: Which Ones Need Urgent Care
- Baby Sweating: When It’s Normal and When to Ask
Sources
- American Academy of Pediatrics. Swollen glands. HealthyChildren.org. https://www.healthychildren.org
- National Library of Medicine. Swollen lymph nodes. MedlinePlus. https://medlineplus.gov
- Kliegman RM, St Geme JW, Blum NJ, et al, eds. Nelson Textbook of Pediatrics. 22nd ed. Elsevier; 2024.
This article is for general education and is not a substitute for individualized medical advice. Always talk with your baby’s health care provider or your own provider about your specific situation. If you think your baby or you may have a medical emergency, call 911.
