Can Growth Spurts Cause Fevers in Babies?

Parents often notice changes in their baby’s behaviour and wonder if these shifts are signs of illness or just another phase of healthy development. One of the most common questions we hear is: Can growth spurts cause fevers in babies?

The short answer is no. Growth spurts do not cause fevers. A fever is a sign of illness or infection and should not be attributed to normal developmental changes.

The Link Between Growth and Temperature

While baby growth spurts are natural periods of rapid physical development, they don’t trigger fevers. During these intense phases, your baby’s body is working hard—but not in a way that raises core body temperature to fever levels.

Growth spurts involve accelerated increases in weight, height, and overall development. These periods typically occur around 2 weeks, 6 weeks, 3 months, and 6 months of age, though timing varies between babies.

Because feeding needs can shift during growth windows, some parents find it helpful to review our formula options by age.

While it’s true that a baby’s metabolism increases during growth, this does not raise body temperature to a fever range^[1].

If your baby develops a fever during a growth spurt period, it’s likely coincidental and not caused by the growth itself.

How Can You Tell the Difference Between a Growth Spurt and an Illness?

Recognising the difference between growth spurt behaviours and symptoms of illness can help parents know when to rest easy and when to seek help.

Signs of a Growth Spurt

• Increased hunger or more frequent feeding
• Mild fussiness or clinginess
• Short-term changes in sleep habits
• Desire for more comfort and physical closeness

Signs of Illness

• Fever (temperature above 38°C)
• Extreme irritability or inconsolable crying
• Listlessness or lack of responsiveness
• Rash or skin discolouration
• Fewer wet diapers (a sign of dehydration)

If you notice illness-related symptoms alongside or instead of growth-related changes, it’s best to monitor closely and reach out to your healthcare provider.

When Should You Contact a Healthcare Provider?

You should contact your pediatrician immediately if:

• Your baby has a fever above 38°C (100.4°F), especially in infants under 3 months old
• The fever is accompanied by rash, lethargy, or dehydration
• Your baby refuses to feed or has significantly fewer wet diapers
• There are other concerning symptoms, such as breathing difficulties, persistent vomiting, or changes in alertness

Even if you’re unsure, it’s always better to consult your healthcare provider. Prompt communication ensures your baby receives the right care at the right time.

FAQs: Growth Spurts and Baby Fevers

Can growth spurts cause low-grade fever?

No. Even a mild or low-grade fever is not a normal part of a growth spurt. Babies may be warm to the touch from extra cuddling or activity, but a true fever means something more than normal growth is happening.

Why do babies get fevers suddenly?

Babies can develop fevers quickly in response to viral or bacterial infections, teething irritation, or post-vaccination reactions^[2-3]. Their immune systems are still developing, making them more sensitive to small changes.

Does a growth spurt increase body temperature?

A growth spurt can slightly increase metabolism, but it doesn’t raise core body temperature enough to be considered a fever.

Disclaimer: This guide is for informational purposes only and should not be used to diagnose health conditions or make changes to medical treatments. Always consult with your healthcare professional for advice.