What are growth spurts?

Ever notice your baby suddenly eating nonstop, getting extra fussy, or seeming a bit bigger overnight? That’s likely a growth spurt. “Growth spurts are brief periods of rapid physical growth in both length and height and/or weight, that occur at predictable times during infancy and childhood, most notably in the first two years and again at puberty,” explains Dr. Marcy Borieux, MD, FAAP, pediatrician at Summer Health. While babies are always growing, a growth spurt is a short, intense phase of accelerated growth, which is why you might notice these sudden changes.

The most intense growth happens during the first 3 months, when babies grow at their fastest rate. After that, growth spurts still happen, but they’re usually less pronounced. Here are the common times when you can expect a growth spurt:

• 4 to 6 weeks 

• 3 months

• 6 months

• 9 months

• 12 months

• 18 months

• 24 months

4 to 6 week growth spurts

Around 4 to 6 weeks, many babies go through a short phase of rapid growth. This is completely normal and a healthy sign of development. For some babies it occurs at the 2 to 3 week mark and then again at 3 months. You may notice that your baby is hungrier than usual, especially in the evening. Your baby may also be fussier or clingy and want to be held. They also may wake more often in the middle of the night or take additional naps during the day.

Signs and symptoms of growth spurts

Growth spurts can show up in different ways, and while every baby is different, there are some common signs that often go hand-in-hand with these rapid periods of growth and development. You might notice:

• Increased hunger: Your baby may seem hungrier than usual and want to feed more often, sometimes back-to-back. 

• More frequent feeding: Whether breastfed or bottle-fed, babies often cluster feed or take in more milk during a growth spurt.

• Changes in sleep patterns: Some babies sleep more during a growth spurt, while others may wake more frequently (especially at night). Sleep disruptions or longer naps can both be signs of a growth spurt. 

• Fussiness and clinginess: Growth can be tiring, and babies might be more irritable, fussy, or in need of extra cuddles and comfort.

• Temporary behavior changes: You might notice your baby is crankier, cries more, or just seems "off." These behaviors usually pass once the growth spurt is over.

Not every child will show all of these signs during every growth spurt. That said, increased hunger, frequent feeding, and sleep changes are the most common and consistent signals that a growth spurt is happening.

Feeding patterns during a growth spurt 

During a growth spurt, babies often seem hungrier than usual—and that’s because they are. You might notice your baby showing signs of hunger, sometimes every hour or two. This is called cluster feeding, and it’s especially common in breastfed babies. “This can temporarily increase milk demand, but maternal milk supply typically adapts to meet increased needs,” explains Borieux. So if your baby seems to be nonstop feeding, it’s normal and a healthy and expected part of development.

Sleeping patterns during a growth spurt 

Don’t be surprised if your baby suddenly starts sleeping more or, on the flip side, waking up more often during a growth spurt. “Growth spurts usually affect sleeping patterns by increasing total sleep time and the number of sleep bouts,” says Borieux. You may notice that they sleep for longer stretches, take an extra nap, or experience disrupted sleep patterns like frequent night waking or difficulty falling asleep. These sleep changes are often linked to the body’s need for extra rest to support growth, as well as increased hunger or general discomfort.

Developmental milestones during growth spurts

You might notice your baby doing something new, like rolling over, babbling, or suddenly reaching for toys, right around the time of a growth spurt. That’s no coincidence. Some research suggests that physical growth spurts are often followed by developmental leaps in motor or cognitive skills.

That said, every baby is different. Some may hit new milestones during or right after a growth spurt, while others follow their own timeline. “The timing of physical and developmental milestones can overlap, but not all milestones are directly linked to growth spurts,” explains Borieux. Physical growth and developmental progress can happen close together, but they’re not always directly connected.

How to support your baby through growth spurts

Growth spurts can feel overwhelming for both babies and parents. Your baby might be clingier, hungrier, or waking more often, and it can be hard to know what’s normal (and function on no sleep). The good news is that these phases are temporary, and there are simple ways to get through them.

Here’s how you can support your baby (and yourself) during a growth spurt:

• Feed on demand: If your baby seems hungrier than usual, go ahead and offer more frequent feeds. This helps meet their growing needs and supports milk supply if you’re breastfeeding.

• Expect temporary changes: Sleep routines and behavior may shift for a few days. Knowing this ahead of time can help you stay calm and remind yourself that things will return to normal soon.

• Monitor growth: Discuss any concerts about your baby’s growth with your local or Summer Health pediatrician to make sure everything is on track. Regular well-baby visits help monitor growth and catch any concerns early.

• Avoid unnecessary supplementation: If breastfeeding is going well, there’s no need to supplement with infant formula. Your supply will naturally adjust.

• Maintain a supportive environment: Make sure feeding and sleep spaces are peaceful and comfortable for you and your baby.

• Track wet diapers: These are good indicators that your baby is getting enough milk.

• Seek medical advice: If your baby’s feeding patterns, weight gain, or mood seem off for more than a few days, don’t hesitate to reach out to your pediatrician. 

How long do growth spurts last?

Most growth spurts are short, typically lasting anywhere from a few days to about a week. However, the length and intensity can vary from one baby to another, and even from one growth spurt to the next. The duration often depends on your baby’s age, temperament, and how their body is developing at the time.

The key thing to remember is: it’s temporary. These intense periods of rapid growth don’t last long, and once they pass, your baby often settles into a new rhythm with new skills or a little extra sweetness to show for it.

When to consult a pediatrician

Consult your local or Summer Health pediatrician if increased feeding frequency, sleep changes, or fussiness during growth spurts are accompanied by poor weight gain, feeding difficulties, persistent vomiting, lethargy, dehydration, or if symptoms persist beyond a few days.

If you have questions about your child’s growth or development, reach out to your local or Summer Health pediatrician for support. Summer Health is a pediatric telehealth platform offering 24/7 care, providing answers for everything from urgent concerns to everyday questions about your child’s health.