One of the hardest parts of early waking is working out whether your baby is waking because they are overtired or because they are undertired. The advice for each is opposite, so getting it wrong makes things worse instead of better.
How to tell the difference
If your baby is overtired, you will usually see other signs alongside the early waking: difficulty settling at bedtime, frequent night wakings, short naps, crying or fighting sleep, and waking grumpy or fussy in the morning. The baby might seem tired all day but struggle to sleep well when given the opportunity. Bedtime may feel chaotic — they seem exhausted, but take a long time to fall asleep or wake shortly after settling.
If your baby is undertired, early waking is usually the only sleep issue. The baby typically settles easily at bedtime, sleeps solidly through most of the night, and wakes happy and alert at 5am (not crying or fussy). Naps may also be easy and restorative. The baby simply does not need as much night sleep because they are getting plenty of rest during the day.
What to adjust if your baby is overtired
If overtiredness is causing the early waking, the goal is to help your baby get more restorative sleep throughout the 24-hour day. This usually means:
- Moving bedtime earlier by 15 to 30 minutes
- Shortening wake windows during the day to prevent overtiredness building
- Creating a very dark and quiet sleep environment to support deeper sleep
- Protecting naps where possible so your baby does not arrive at bedtime already exhausted
What to adjust if your baby is undertired
If undertiredness is the issue, your baby is getting more sleep than they need during the day, which reduces their night sleep requirement. To shift the early wake, you will need to reduce total daytime sleep slightly. This might mean:
- Capping nap length (especially the last nap of the day)
- Stretching wake windows slightly to build more sleep pressure by bedtime
- Moving bedtime slightly later if your baby has very long nights but still wakes early
- Considering whether your baby is ready to drop a nap (common around nap transition ages)
Why guessing wrong makes it harder
If you treat an overtired baby as undertired — by pushing bedtime later, capping naps, or stretching wake windows — you increase overtiredness and make the early waking worse. Sleep becomes more fragmented, your baby becomes more unsettled, and the problem compounds.
If you treat an undertired baby as overtired — by moving bedtime earlier and prioritising longer naps — you give them even more sleep than they need, which pushes the natural wake time earlier. The baby may start waking at 4:30am instead of 5am, and the cycle gets harder to break.
The default assumption should be overtiredness
If you are uncertain which applies, start by assuming overtiredness. It is far more common, and the adjustments (earlier bedtime, protecting naps, shortening wake windows) are gentler and lower-risk. If your baby is overtired, you will usually see improvement within a few days. If nothing changes or the early waking gets worse, undertiredness is more likely, and you can then make the opposite adjustments.
A sleep consultant can help you assess whether your baby is overtired or undertired by looking at the full 24-hour picture — not just bedtime or wake time in isolation.
