Growing Pains or Lyme Disease? How to Tell the Difference
LEG PAIN AT NIGHT?
CALLED “GROWING PAINS”?
COULD THIS BE LYME DISEASE?
Growing pains or Lyme disease is a common question when children develop leg or joint pain. While growing pains are often assumed, Lyme disease can present with similar symptoms—sometimes delaying diagnosis.
When “growing pains” is wrong, children can go months without the right diagnosis.
Understanding the difference between growing pains and Lyme disease can prevent missed diagnosis while a treatable infection continues to affect joints and function.
For a full overview of symptom patterns, see our
Lyme Disease Symptoms Guide.
For more on misdiagnosis in children, see
Pediatric Lyme Disease.
Growing Pains or Lyme Disease: What Parents Should Know
Both conditions can cause leg discomfort during active growth years and may worsen after activity. These similarities often lead to misdiagnosis.
Growing pains are a diagnosis of exclusion. When Lyme disease is present, labeling symptoms as growing pains can delay testing and treatment.
The difference lies in timing, pattern, physical findings, and associated symptoms.
Growing Pains vs Lyme Disease: Key Differences
| Feature | Growing Pains | Lyme Disease (Lyme Arthritis) |
|---|---|---|
| Timing | Night only | Day and night |
| Location | Muscles | Joints (especially knee) |
| Swelling | Never | Common |
| Limping | No | Often present |
| Duration | Minutes to hours | Days to weeks |
| Activity impact | Normal during day | Reduced activity |
When Growing Pains Aren’t Growing Pains
True growing pains:
- Occur only at night
- Involve muscles—not joints
- Resolve by morning
- Do not affect daytime activity
Growing pains never cause:
- Joint swelling
- Limping
- Fever
- Limited movement
Red flags for Lyme disease:
- Joint swelling (especially knee)
- Persistent pain lasting days to weeks
- Daytime symptoms
- Limping or refusal to walk
- Migratory joint pain
- Fatigue, headaches, or rash
- History of tick exposure
Even one red flag warrants evaluation.
How Lyme Arthritis Presents in Children
Lyme arthritis most commonly affects large joints—especially the knee.
- Visible swelling
- Warmth and stiffness
- Reduced range of motion
- Limping or avoidance of activity
Symptoms often persist for days to weeks and may migrate between joints.
Importantly, Lyme arthritis may appear months after tick exposure, when early signs such as rash are no longer present.
The Diagnostic Challenge
Growing pains often lead to reassurance without testing.
Lyme disease requires clinical suspicion.
Children with Lyme arthritis typically test positive because symptoms occur later, after antibody development.
Clinical insight: A child with knee swelling after summer outdoor activity should be evaluated for Lyme disease.
For more, see Lyme test accuracy.
Why This Distinction Matters
Growing pains resolve on their own.
Lyme disease requires treatment.
Without treatment, inflammation may persist and lead to prolonged symptoms.
Early recognition changes outcomes.
Clinical Takeaway
Growing pains and Lyme disease can appear similar—but key differences in timing, swelling, and function help distinguish them.
Joint swelling, limping, daytime symptoms, or persistent pain should not be attributed to growing pains without evaluation.
Recognizing these patterns can prevent delayed diagnosis in children.
Frequently Asked Questions
How can I tell if my child has growing pains or Lyme disease?
Growing pains occur only at night, in muscles, and never cause swelling or limping. Lyme disease causes joint swelling, daytime symptoms, and functional changes.
Can Lyme disease cause leg pain at night?
Yes, but Lyme disease typically also causes daytime symptoms and may involve joints rather than muscles.
What does Lyme arthritis look like in children?
It typically presents with knee swelling, warmth, stiffness, and reduced motion lasting days to weeks.
Do growing pains cause knee swelling?
No. Swelling should always be evaluated.
Can a child have both growing pains and Lyme disease?
While possible, persistent or joint-based symptoms should not be attributed to growing pains without evaluation.
Related Reading
- Pediatric Lyme Disease
- Knee Swelling in Lyme Disease
- MRI and Lyme Arthritis
- ADHD vs Lyme in Children
Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.
Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention
