Fussy Baby? Here Are All the Possible Things That Could Be Happening

it’s not always teething, grandma

by: ggm team

Whenever your baby is fed, changed, warm, rested and doesn’t have hair wrapped around her finger, it can be confusing (if not frightening) when she starts being, as we all like to say, “fussy,” without a clear reason.

Your grandma will swear she’s teething and bring you a frozen washcloth but in the event she’s wrong, here’s a briefer on all the possibilities.

Growth spurt

Your baby’s main job is to grow. This probably sounds easier than your office job, but it’s hard! Think about it: your baby will triple in weight by her first year1. Proportionally speaking, that’s like a 140-pound person growing to 420 pounds. That’s a lot of… stretching and enlarging.

When It Happens:

Babies don’t grow incrementally like hair. They grow in spurts—and although they can happen at any time, the first one usually happens in 7-10 days after birth, according to Clare Bush, MD, assistant professor of Pediatrics at Columbia University Medical Center.

Other times growth spurts are commonly seen are at 3 weeks, 6 weeks, 3 months and 6 months.2

Telltale Signs:

  • A bigger body means a bigger stomach, which means she’ll want more food. Don’t be surprised if your little barnacle gets hangry during a spurt.
  • She might need more sleep too. Unfortunately, this might mean disrupted sleep patterns: sleeping longer during the day (and not at night!) or sleeping in irregular bursts. While it can be a pain for you, her need for more sleep means she’s growing, and that’s a good thing!

What can you do about it?

  • A ravenous baby means you may have to feed her more frequently. You might feel like a feeding machine during these growth spurts but rest assured: she is getting what her little body needs to grow.
  • Be flexible. Your fussy baby may sleep in irregular bursts during a growth spurt, so you might find that you’ll also have to get rest when she rests.

Wonder Weeks

Fussiness in your baby might also be attributed to the Wonder Weeks, periods that describe what is happening in your baby’s cognitive development. According to the app, Wonder Weeks are “predictable leaps in your baby’s development and often are accompanied by changes to her behavior, such as fussiness.”

When It Happens:

Frans Plooij, PhD and Hetty van de Rijt, PhD, a husband-and-wife research team from the Netherlands, found predictable leaps in a baby’s cognitive development—for all babies. They also found each of these leaps were accompanied by clinginess, crankiness, and crying3.

In your baby’s first year, she will experience these fussy periods around weeks 5, 8, 12, 19, 26, 37, 46, 55 after their due date (not actual birthday). Keep in mind many moms find their babies act fussy well before or after the given timelines, so don’t go crazy and add these all to your iCal.

Each fussy week corresponds to a mental leap:4

  • 5 weeks – The World of Changing Sensations (noticing sensations, seeing more visually)
  • 8 weeks – The World of Patterns (differentiating patterns in what they see)
  • 12 weeks – The World of Smooth Transitions (making smooth movements, perceiving changing things around him)
  • 19 weeks – The World of Events (differentiating between a series of smooth transitions like waving, clapping)
  • 26 weeks – The World of Relationships (understanding spatial relationships)
  • 37 weeks – The World of Categories (looking and comparing objects)
  • 46 weeks – The World of Sequences (learning cause and effect, things that happen in sequences)
  • 55 weeks – The World of Programs (understanding actions in a series, beyond simple sequences)

Sometimes by the time you see these mental changes in your baby, they may have already gone through their clingy, cranky, crying phase.

Telltale signs:

  • Crankiness, clinginess and crying are the biggest behavioral changes you may see in your baby when she’s going through a mental leap. So much information for their little growing brains! And each mental leap can be an overwhelming time in their lives when their world changes yet again.
  • Remember all babies react to these leaps differently. Some parents don’t even notice when there’s a leap.

What can you do about it?

  • Provide comfort and attention by soothing, holding or carrying her more often (hello, baby carriers!). These cognitive changes may feel scary so help her feel safe and secure to explore.
  • Nurture the skill your babe is getting ready to learn by helping her to explore it! For example, if she’s approaching the World of Categories week, you could expose him to objects that allow for comparing, like two different colored blocks.  


Colic usually gets the blame for fussy babies. (It’s basically the original explanation for fussy babies.) The incessant crying. The inconsolable distress. The fist-clenching, face-reddening, leg-stiffening. According to the Mayo Clinic, colic might be related to a growing digestive system that isn’t yet able to balance bacteria, tolerate certain foods/proteins or handle gas.5 But really, nobody definitively knows why colic happens.

When It Happens:

Colic usually starts around 2 weeks of age, peaks around 6-8 weeks and then gradually goes away by 3-4 months.

Telltale Signs:

In 1954, Dr. Wessel, an American pediatrician coined the term colic, to describe babies who cried for:6

  • 3 hours a day
  • More than 3 days a week
  • For over 3 weeks

What can you do about it?

  • For breastfed babies, keep a diary to track what you’re eating.
  • For formula-fed babies, you may need to try a formula with different ingredients.
  • You could also try burping your baby or keeping her upright to keep possible gas troubles at bay.

P.U.R.P.L.E. Crying

There’s also the possibility that fussiness is just part of your sweet cherub’s nature. Alas, fussiness doesn’t always mean there’s necessarily something wrong. Dr. Ronald Barr, a developmental pediatrician, coined the term “the period of PURPLE crying” to help new parents understand these crying/fussy periods in your baby’s life7.

When It Happens:

Like colic, the period of purple crying can begin at 2 weeks of age and continue on until 3-4 months, with the peak of crying at 2 months. Fear not, though. Dr. Barr notes that this is called a “period” (in that it does not last forever).

Telltale Signs:

This type of crying is characterized by the acronym: P-U-R-P-L-E.

            P- Peak of Crying – baby cries more and more each week

            U- Unexpected – crying for no reason

            R- Resistant to soothing

            P- Pain – it might look like your baby is in pain

            L- Long-lasting – can last up to 5 hours a day

            E- Evening – it may occur more in the evenings or late afternoon

What can you do about it?

PURPLE crying was defined so new parents know this type of crying is normal. Your baby is OK. Get some help. It might not solve his crying, but it will do wonders for you psychologically and emotionally (and ultimately isn’t that the most important thing?!).


Tell anyone born in the 40s about your baby’s fussiness and they’ll be pretty adamant that “it’s teething.”  And while it’s hopefully not causing your baby too much pain, there might be some discomfort and fussiness around the emergence of their little teeth8.

When It Happens:

Believe it or not, teething can happen as early as 3 months! Most commonly, though, it starts between 4-7 months. (But like with all things, your baby has her own timeline so take these averages with a grain of salt.)

Telltale Signs:

  • Lots of drooling.
  • Baby suddenly wants to chew on EVERYTHING. (If you’re breastfeeding: ouch?!)
  • Her little gums might be tender or swollen.

What can you do about it?

  • Let baby gnaw on hard plastic or rubber teething toys (NOT ones made of silicone, marble or wood).
  • Try a cold washcloth or teething toy.
  • Gently massage her gums with your clean fingers.

Sleep regression

Fun fact: Dr. Michelle Lampl from Emory University discovered that babies grew in length after a bout of disturbed sleep.9   Great news for baby, but not so great for you, as this might mean more frequent wakings, napping more during the day and less sleeping at night. Changes in your baby’s sleep patterns are called sleep regressions.  

When It Happens:

Sleep regressions can happen at any time, but are commonly seen at 4, 6, 8 and 12 months during the first year of your baby’s life.10

Telltale Signs:

  • Just when your baby is starting to sleep more, there is a change in her sleep habits:
    • She might wake up more often.
    • She might refuse to sleep.
    • She might sleep for shorter periods.

What can you do about it?

  • Keep a consistent sleep routine (i.e. bath, story, song). This will help signal to your little one that it is time to sleep.
  • Take your baby outside during the day. Natural light and some fresh air will do wonders for helping your baby differentiate night and day.
  • Make sure your baby’s environment is conducive to sleep (dark, cool and white-noisy).

Witching hour

The witching hour is the time of the day when your normally happy baby cannot be consoled or soothed.  Dr. Harvey Karp, M.D, author of the Happiest Baby on the Block, writes, “Just like everyone else, babies get frazzled by the end of the day.” 11

When It Happens:

The late afternoons/evenings can be the busiest time in the house: your partner is coming home, the older siblings are back from school, you’re trying to multi-task (homework! dinner!). This is crazy for you, but it can also make for an overwhelmed, overstimulated baby.

Telltale Signs:

Chaya Kulkarni, the director of Infant Mental Health Promotion at the Hospital for Sick Children in Toronto,12 says your baby maxes out on the amount of stimulation she can take on by this time. She might:

  • seem tired, but refuse to sleep
  • look away, or close her eyes
  • cry and fuss

What can you do about it?

  • Get to know what works for your baby in terms of decreasing stimulation during the dreaded witching hour. Some babies might be soothed by being held close, while others might prefer being removed from the busy-ness of it all, retreating to a quiet, dark room to calm down.


  1. https://www.mayoclinic.org/healthy-lifestyle/infant-and-toddler-health/expert-answers/infant-growth/faq-20058037
  2. https://www.parents.com/advice/babies/baby-development/what-are-the-signs-of-a-growth-spurt/
  3. https://www.thewonderweeks.com/scientific-history/
  4. https://www.thewonderweeks.com/babys-mental-leaps-first-year/
  5. https://www.mayoclinic.org/diseases-conditions/colic/symptoms-causes/syc-20371074
  6. https://americanpregnancy.org/first-year-of-life/colic/
  7. http://purplecrying.info/what-is-the-period-of-purple-crying.php
  8. https://www.mayoclinic.org/healthy-lifestyle/infant-and-toddler-health/in-depth/teething/art-20046378
  9. https://aasm.org/study-is-the-first-to-link-sleep-duration-to-infant-growth-spurts/
  10. https://www.childrens.com/health-wellness/sleep-regression-in-infants-and-toddlers
  11. https://www.parents.com/baby/care/crying/afternoon-angst/
  12. https://www.todaysparent.com/baby/how-much-infant-stimulation-is-too-much/



shop lists

The Unconventional Sleep Deprivation Survival Guide for New Moms

Most new parents are shocked into a state of perpetual horror when they live to see the sleep deprivation of the newborn/infant days.   We’ve all been warned by our mother-in-laws and baby-shower attendees that parents are IRL zombies, but very few people take...

Sign up for our Newsletter

Support, solidarity and self-care for new mamas. If that’s you, get on the list!

related posts

11 Not-As-Obvious Skin Habits That Are Bad for Your Complexion

11 Not-As-Obvious Skin Habits That Are Bad for Your Complexion if pretty skin is your goal, read this by: team Unless you have been living under a rock, you know that smoking, not wearing sunscreen and going to bed with your makeup on hardly produces the coveted look...

Pin It on Pinterest