Why does my baby wake up crying?

Is your baby waking up crying in the middle of the night, the morning, or right after a nap?

You are definitely not alone. Both my girls had phases where they would suddenly wake up crying instead of cooing and happy!

In the first year or so, crying is your baby’s main way form of communication with you.

Sometimes waking up crying is just a phase, or just their way of saying "hey!! I'm up!! You should be too" lol. Other times, it can signal sleep struggles, discomfort, hunger, or separation anxiety.

Understanding why can help you respond calmly, reduce stress for both of you, and take small, practical steps to make nights (and naps!) a little easier.

Here are the 6 most common reasons your baby might be waking up crying—and what you can do about each:

1. Normal sleep transitions

Some babies are naturally noisy sleepers. Fussing, whimpering, or small cries between sleep cycles is part of normal sleep. A calm environment, consistent routines, and gentle reassurance can make these wake-ups less stressful for both of you.

2. Overtiredness

Overtired babies often struggle to stay asleep, wake more frequently and/or wake up crying! Long stretches awake during the day along with short naps, or irregular routines can make stress spike and disturb sleep.

Tip: watch for sleepy cues and aim to put your baby down before they get overtired. It can take a few days to break the cycle, but I have extra tips on doing that right here!

3. Hunger 

Even after a long stretch of sleep, your baby might need a feed—especially if daytime feeds haven’t been filling enough.
Sometimes feeding patterns contribute—reverse cycling (more feeds at night than during the day) can leave your baby waking hungry. Encouraging fuller daytime feeds often helps.

4. Discomfort or pain

Babies cry when something feels off. Common triggers include:

✶ Wet or dirty diaper
✶ Gas, reflux, tummy aches
✶ Diaper rash or sensitive skin
✶ Teething

5. Separation anxiety

Separation anxiety typically peaks around 8–10 months but can appear earlier or later. Your baby may cry at bedtime, nap time, or when they notice you’re gone. Gentle reassurance, consistent routines, and helping your baby feel secure can make these wake-ups calmer and shorter.

6. Temperament

Just like us, some babies are “not morning people.” They may wake up groggy, grumpy, or a little disoriented, especially after naps or a long stretch of sleep. This isn’t about you doing something wrong—it’s just part of their natural temperament.

Understanding your baby’s temperament can make a huge difference in how you approach sleep, wake-ups, and bedtime routines. Learn more in my All About Temperament blog.

What to remember: 

Babies waking up crying is very common, and not always cause for concern. Knowing why your baby wakes up….normal sleep transitions, overtiredness, hunger, discomfort, separation anxiety, or temperament—helps you respond the best way possible.

Need more sleep help? I’ve got you covered! 

✶ 4–24 months: Baby Sleep Course for step-by-step routines, independent sleep skills, and night waking solutions.
✶ Newborns: Newborn Sleep Foundations for healthy sleep rhythms and confidence navigating unpredictable nights.