6 Month Old Suddenly Won’t Sleep Through the Night

If your baby was sleeping well — and suddenly isn’t — it can feel confusing.

More waking. Shorter stretches. More unsettled nights.

You might be wondering:

“What changed?”

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At around 6 months, most babies need roughly 12–15 hours of total sleep in a 24-hour period, including naps.

This usually includes:

• 10–12 hours overnight (often with some waking)
• 2–3 hours of daytime sleep

But sleep at this age is not always consistent.

Even babies who were previously sleeping longer stretches can suddenly start waking more often.

The truth is that this is very common around 6 months.

In most cases, it’s not a sign that something is wrong, but part of a normal developmental transition as sleep becomes lighter and less predictable than before.

Sleep at this age often looks less predictable than before — and that’s part of the transition.

Things to Check First

Before assuming this is just a developmental phase, it’s worth ruling out a few common factors.

Most sleep changes at this age are normal — but sometimes there’s a simple reason behind them.

1. Physical discomfort

Check for anything that might be making your baby uncomfortable, including teething, illness, congestion, growth spurts, or digestive discomfort.

Even small changes can affect sleep more than expected.

If your baby seems unusually unsettled or in pain, it’s always worth checking with your GP or health visitor.

2. Hunger or feeding changes

Around 6 months, feeding patterns often shift.

• starting solids
• changes in milk intake
• growth-related hunger

Some babies begin waking more simply because their needs have changed.

3. Overtiredness or undertiredness

Sleep can become more sensitive at this stage.

• too much awake time → overtired
• too little awake time → not ready for sleep

Both can lead to more night waking.

4. Environmental changes

Even small changes can affect sleep:

• room temperature
• lighting
• noise
• changes in sleep space

Babies at this age are becoming more aware of their surroundings.

If you’re currently supporting more night waking or feeding overnight, this can help you do it safely
→ Co-Sleeping With a Baby: Bedsharing Safety Guide for New Parents

5. Developmental changes

Once you’ve ruled out the above, the most likely cause is development.

In most cases, sleep changes at this age are not something being “wrong” — they’re part of growth.

Why Sleep Changes Around 6 Months

Around 6 months, several important developmental changes happen at once.

Your baby becomes more aware of their surroundings, begins recognising separation more clearly, develops new physical skills like rolling or sitting, and transitions into more mature sleep cycles.

Because of this, sleep often becomes lighter, less predictable, and more easily disrupted than before.

This is often called the “6 month sleep regression,” but it’s usually less of a regression and more of a developmental shift. Even babies who previously slept longer stretches may suddenly begin waking more often, resisting sleep, or needing extra comfort overnight.

Common Changes You Might Notice

• waking more often overnight
• shorter sleep stretches
• needing more comfort
• resisting sleep they previously accepted

That’s normal at this stage.

If your baby also wakes immediately when put down, this is often related
→ Baby Wakes Up When Put Down — Here’s Why (And What Actually Helps)

What Actually Helps

The goal isn’t to force longer sleep.

It’s to support your baby through the change.

1. Keep the Environment Calm and Predictable

A simple, consistent sleep space usually helps most at this age.

Low stimulation, familiar surroundings, and a predictable setup can all make settling feel easier — especially as babies become more aware of their environment around 6 months.

Keeping lighting soft during night waking can also help avoid fully waking your baby. Many parents find a dimmable night light useful for feeds, settling, or overnight changes without overstimulating the room.

JolyWell Dimmable Easy Touch Night Light

2. Respond Without Overstimulating

When your baby wakes overnight, keeping interactions calm and predictable often helps them return to sleep more easily.

Try to:

• keep lights low
• limit stimulation
• respond calmly and consistently

Simple things like keeping soft muslin cloths nearby for feeds, spit-up, or quick clean-ups can also make night waking feel less disruptive.

If your baby uses a sleep sack or wearable blanket, keeping temperature consistent overnight may also help reduce unnecessary waking caused by discomfort.

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3. Expect Temporary Disruption

This phase often passes on its own.

Sleep may look different for a while.

4. Support Daytime Development

More movement and exploration during the day can help balance night disruption.

At this age, simple floor play and movement opportunities are enough.

5. Avoid Overcomplicating Sleep

It can be tempting to change everything at once.

New routines.
New methods.
New expectations.

But often, less change works better.

Consistency supports your baby more than constant adjustment.

What Not to Do

You don’t need to rush into “fixing” sleep, remove comfort, or push independence before your baby is ready.

At this stage, responsiveness and consistency often support sleep more effectively than constant adjustment.

When Does This Phase End?

For most babies, this stage gradually settles.

You may notice:

• longer stretches returning
• easier settling
• fewer night wakings

It doesn’t happen overnight.

But it does shift.

Final Thoughts

This stage can feel exhausting, especially during long nights and unpredictable sleep.

But the same developmental changes disrupting sleep now are also supporting awareness, movement, and independence later on.

Even if it doesn’t feel like it at 3am.

Frequently Asked Questions About 6 Month Sleep Changes

Why is my 6 month old suddenly waking at night?

Night waking often increases around 6 months due to development.

Your baby is becoming more aware, learning new physical skills, and transitioning into more mature sleep cycles.

This can make sleep lighter and more easily disrupted — even if they previously slept well.

Is the 6 month sleep regression real?

What’s often called a “sleep regression” is actually a developmental shift.

Your baby’s sleep is becoming more structured and adult-like, which can temporarily lead to more waking.

It’s not a step backwards — it’s a sign of progress.

Why does my 6 month old wake every 2 hours?

Frequent waking can happen when sleep cycles change.

Your baby may now wake more fully between cycles and need support to settle again.

Other factors like hunger, development, or overtiredness can also contribute.

Should a 6 month old be sleeping through the night?

Some babies do — but many don’t.

Night waking at this age is still very normal.

Sleep patterns vary widely, and waking doesn’t mean something is wrong.

Why is my 6 month old harder to settle at bedtime?

Increased awareness can make bedtime feel different.

Your baby may notice more about their surroundings, resist separation, or feel more alert.

This can make settling take longer than before.

Could teething cause night waking at 6 months?

Yes — teething can affect sleep.

Discomfort, even mild, can make it harder for your baby to settle or stay asleep.

This is often temporary and tends to pass as symptoms ease.

How long does the 6 month sleep phase last?

This stage doesn’t have a fixed timeline.

For many babies, sleep gradually improves over a few weeks as they adjust to developmental changes.

It tends to ease rather than suddenly stop.

What helps a 6 month old sleep better at night?

Simple, consistent support makes the biggest difference:

• a calm, predictable sleep environment
• consistent routines
• responding gently to night waking
• avoiding overstimulation

Over time, this helps your baby feel secure and settle more easily.