We’ve all had the occasional rough night—but if you’re running on low sleep more often than not, your body will start waving red flags. Sleep deprivation doesn’t always look like nodding off at your desk (though that’s a big one). In fact, some of the signs are surprisingly subtle—and easy to brush off as "just stress" or "just being busy."
Here are 5 key signs you might be sleep deprived, and what you can do about it.
1. You're Forgetting the Little Things
Can’t remember where you put your keys? Struggling to recall what someone just said? Poor sleep directly affects short-term memory and your brain’s ability to process and store new information.
When you're sleep deprived, your hippocampus—the area of the brain that processes memory—isn't functioning at full capacity. Overnight, sleep is responsible for transferring memories from short to long term storage, retaining the information learnt that day.and clearing the way for the new the next day. However, if you haven’t had sufficient sleep, deep sleep and / or REM sleep, this may not be happening for you.
2. You're Moodier Than Usual
Irritability, emotional reactivity, feeling constantly on edge? Sleep and mood are deeply linked. Lack of sleep increases cortisol (the stress hormone), so much so that it can increase by 37% with just one night of insufficient sleep.
Further studies show poor sleep can lead to mood swings, anxiety, and decreased patience, again, just after 1 night. If you’re snapping at loved ones or feeling overly sensitive, it might be time to check your sleep—not just your to-do list.
3. You're Always Reaching for Sugar or Caffeine
When your body is low on energy, it looks for quick fixes—sugar and caffeine. Sleep deprivation disrupts hormones like ghrelin and leptin - grehlin increases, leptin decreases, leading to an insatiable appetite and cravings for sugar.
This can set off a cycle of energy crashes, poor food choices, and even unwanted weight gain—all because you’re not sleeping enough.
4. You're Getting Sick More Often
Sleep is when your body does its best repair work—especially for your immune system. In fact, research shows that people who get less than 6 hours of sleep per night are four times more likely to catch a cold than those who get at least 7.
If you’re constantly battling bugs, feeling rundown, or taking longer to recover from illness, your sleep quality (or lack thereof) could be to blame.
5. You're Falling Asleep the Moment Your Head Hits the Pillow
This might sound like a good thing, but falling asleep immediately—within five minutes of lying down—can actually be a sign of severe sleep deprivation. Healthy sleep latency (the time it takes to fall asleep) is usually between 10–20 minutes.
If you’re crashing the moment your head hits the pillow, it’s your body playing catch-up from chronic sleep debt.
The Takeaway: Your Body Keeps Score
Sleep isn’t optional—it’s essential. If you’re noticing these signs creeping into your day-to-day life, it’s time to prioritise rest… stat. Sleep is the tool to success - make sure it’s in your toolkit. Stay tuned for further articles on how to improve your sleep, directly from myself, your sleep coach, and Australia’s Leading Sleep Expert.
Written by Olivia Arezzolo, Australia’s Leading Sleep Expert
