Bedtime is a fight. Again. And the instinct is always the same: they must be overtired, push the next sleep earlier. Except sometimes that makes it worse, because the actual problem was the opposite - they weren't tired enough yet.
Telling these two apart is one of the more genuinely useful skills in early sleep, mostly because the fixes point in opposite directions.
What overtired usually looks like
- A "second wind" - suddenly wired, giggly, or hyperactive right when sleep should be approaching
- Arching away from you, crying hard as soon as they're laid down
- Rubbing eyes, yawning, or glassy-eyed alongside the fussing
- Waking in a short amount of time after finally going down, upset, and hard to resettle
What undertired usually looks like
- Calm but wide awake at bedtime - chatting, playing, showing no sleepy cues at all
- Taking a long time to fall asleep, but not distressed while doing it
- Waking early from a nap or in the morning, alert and ready to go rather than groggy
- Generally content - the resistance is more "I'm not ready" than "I'm falling apart"
Why they get confused so easily
Both can look like 'fighting sleep' from the outside, and both can involve crying at bedtime - which is exactly why the instinct to just push bedtime earlier doesn't always land. An overtired baby has flooded their system with stress hormones that make settling harder, not easier. An undertired baby simply hasn't built up enough sleep pressure yet to fall asleep easily.
The clearest tell is usually what happens in the half hour before the meltdown: a wired, manic energy points to overtired; a chatty, calm alertness points to undertired.
What to actually do about each
- Overtired: move the next sleep earlier and shorten the awake window, keep the wind-down extra calm and low-stimulation
- Undertired: extend the awake window slightly, add some active, engaging time beforehand rather than winding down too early
- Either way, small adjustments (10-15 minutes) work better than big swings - age-appropriate awake windows are a good starting reference, not a rulebook
The trial-and-error part nobody mentions
This isn't something you diagnose once and solve forever - awake windows shift as babies grow, so what worked last month may need nudging again this month. Treat it as an ongoing, small experiment rather than a fixed formula.
If bedtime is a fight, look at the 30 minutes before it rather than the clock. The clues are usually right there.