Why You Keep Waking Up at 3am (And It's Not Your Anxiety)

If I had to pick one habit that matters more than any other for metabolic health, it would be sleep. Not diet. Not exercise. Sleep.

That's not hyperbole. A study published this month found that insufficient sleep had a greater impact on life expectancy than diet, physical activity, or social isolation—second only to smoking. And here's what makes sleep different from everything else you do for your health: one night of sleep deprivation can impair your insulin sensitivity to a similar degree as six months on a high-fat diet. One night.

You can eat perfectly and exercise daily, but if you're not sleeping, you're fighting an uphill battle.

There is no supplement, no pill, no biohack that replicates what happens when you actually sleep.

Sleep is a topic I could write about endlessly—there's so much to it. Can't fall asleep in the first place? That's often a blood sugar issue too, but a different mechanism. I'll be covering that and more in a whole sleep series I'm launching in 2026.

But today, let's talk about a specific pattern: the maddening middle-of-the-night wake-up.

You know the feeling. You're sleeping fine, and then suddenly—you're wide awake. Heart beating a little too fast. Mind already racing. You glance at the clock: 3:17am. Again.

You've probably blamed stress. Or anxiety. Maybe you've Googled "why do I wake up at 3am" and fallen down a rabbit hole that left you more confused than when you started.

Here's what most of those articles miss: that middle-of-the-night wake-up often isn't caused by your anxiety. It's causing it.

Why 3am? It's Not Random.

There's a reason so many people report waking between 2 and 4am specifically. Two things are happening in your body at that time—and when they collide, you wake up.

First: Your body is preparing for morning.

Cortisol—the hormone that helps you feel alert—follows a 24-hour rhythm. It drops to its lowest point around midnight, then starts rising in the early morning hours to help you wake up. This rise typically begins around 2-3am, with a big peak after you actually get out of bed.

In a healthy system, this rise is gradual. You don't notice it. You sleep right through it and wake up when your alarm goes off.

But if your stress levels are already elevated—if your body has been running on cortisol all day—that gentle 3am rise can be enough to push you over the edge. Think of it like a cup that's already full. When a little more gets added, it overflows. You wake up.

Second: Your blood sugar may be crashing.

While you sleep, your body still needs fuel. Your brain in particular is metabolically demanding—it's working all night consolidating memories and cleaning house.

When your blood sugar drops too low, your body treats it as an emergency. It releases cortisol and adrenaline to mobilize stored glucose and bring your levels back up. This is a survival mechanism.

The problem is that adrenaline isn't subtle. It increases your heart rate, sharpens your senses, and pulls you straight out of sleep. That racing heart, that sudden alertness, those anxious thoughts? That's not anxiety waking you up. That's adrenaline doing its job. The anxious thoughts come after—your brain trying to make sense of why you're suddenly wide awake.

The Double Whammy

Here's where it gets interesting: these two things often happen together.

If your blood sugar has been unstable during the day—spiking and crashing—your body has been pumping out cortisol to compensate. By the time you go to bed, your stress cup is already close to full.

Then around 3am, two things happen at once: your natural cortisol starts its morning rise AND your blood sugar dips low enough to trigger more stress hormones. Your cup doesn't just overflow—it floods.

This is why the 2-4am window is so common. It's when your circadian rhythm and your metabolic state collide.

Why Your Doctor Hasn't Mentioned This

Standard bloodwork almost never catches this pattern.

Fasting glucose is measured in the morning—after your body has already corrected the overnight drop. By the time you're sitting in the lab, your cortisol has done its job and your numbers look perfectly normal.

You might be told your blood sugar is "fine" while waking up every night because of blood sugar.

What's Actually Setting You Up For This

Several things can prime you for a rough night:

• Dinner time. If dinner was at 6pm and you went to bed at 11pm, that's a long stretch for your body to maintain stable glucose—especially if dinner was carb-light. You may simply run out of fuel before morning.

  On the flip side, a big meal too close to bedtime creates a different problem. When you eat—especially carbs—your body releases insulin to manage the glucose. But insulin and melatonin (your sleep hormone) don't play well together. High insulin suppresses melatonin production, making it harder to fall into deep, restorative sleep. So even if you fall asleep, you're not sleeping as deeply—which makes you more likely to wake when that 3am cortisol rise hits.

  
  

  Too early and you crash. Too late and you never get deep enough. The window matters.

• What you eat for breakfast. Starting your morning with high-carb foods—oatmeal, fruit, toast —spikes your blood sugar first thing. What goes up must come down, and that crash sends your body scrambling for more sugar to rebalance. So you reach for a snack, spike again, crash again. The sleep problem often starts at breakfast.

  
  

• Chronic stress. When you're running on stress for weeks or months, you're constantly tapping into your glucose reserves and keeping cortisol elevated. By bedtime, your cup is already almost full—and there's no buffer for the natural 3am rise.

  
  

• Unstable blood sugar all day. If you're spiking and crashing from morning to night, that rollercoaster doesn't stop when you go to bed. It follows you into sleep—and sets you up for a crash in the early hours.

• Chronic life stress. Even if your eating is dialed in, running on stress for weeks or months keeps cortisol elevated around the clock. By bedtime, your cup is already full—and there's no buffer for the natural 3am rise.

  
  

• Alcohol. That glass of wine initially raises blood sugar, then your liver prioritizes processing the alcohol over maintaining glucose. The result is often a crash a few hours later—right around 3am.

Seeing What You Can't Feel

This is exactly why I've become such an advocate for continuous glucose monitoring. You can't feel your blood sugar dropping at 2am. You can only feel the aftermath—the adrenaline, the waking, the racing thoughts.

But with a CGM, you can look at the data and see exactly what happened: the slow decline after dinner, the dip into the 60s at 2:30am, the sharp rise as your stress hormones kicked in.

Once you see it, you can fix it. With food and timing—not medication, not sleep aids.

What You Can Try Tonight

Move dinner later or add a small bedtime snack. Something with protein and fat—a spoonful of almond butter, some cheese, half an avocado. You're not looking for a big meal, just enough to extend your glucose stability through the night.

Watch the alcohol. If you're drinking in the evening and waking at 3am, try a week without. The correlation is often striking.

Look at your daytime eating. If you're skipping meals, relying on coffee until noon, or riding a glucose rollercoaster all day, that instability follows you into the night.

Address the stress. If your cup is full before you even go to bed, the 3am rise will keep waking you up no matter what you eat. This is where the bigger work comes in—and why sleep can't be fixed in isolation.

If this sounds confusing, you're not alone. The body is a wonderful and complicated system. Something as simple as dinner timing can have completely different effects on your sleep depending on when you eat, what you eat, and what your metabolism was doing all day. Too early, too late, too heavy, too light—each one pulls a different lever.

This is exactly why I'm so fascinated with learning about the body's hormones and how our daily habits can create real, lasting change. And it's why working with an endocrine health coach is so much more effective than trying to piece it together from contradictory Google search results.

Waking up exhausted doesn't have to be your destiny forever. Sometimes it's just biochemistry—and biochemistry can be changed once you can see what's happening.

Interested in finding out what your glucose is really doing while you sleep? I'm opening up spots for CGM monitoring next week. Stay tuned.

Please note: This article is for educational purposes only and isn't a substitute for personalised medical advice. Always work with your healthcare provider before making changes to any medications or treatments. Ultimately, you are the one responsible for your health choices—and that's actually empowering.