Sleep And Anxiety: How Your Crappy Sleep is Related To Anxiety

Ever had one of those nights where you just can’t seem to fall asleep? You toss and turn, watching the hours tick by, knowing that the less sleep you get, the worse you’ll feel in the morning. And sure enough, when morning comes, you’re greeted with a foggy brain, a racing heart, and a sense of dread about the day ahead. You reach for a cup of coffee to try and kickstart your day, but instead of feeling more awake, you find yourself even more anxious and jittery. And so, the cycle begins – poor sleep leading to anxiety, leading to more coffee, leading to more anxiety, and on and on it goes. If this scenario hits close to home, you’re not alone. The relationship between sleep and anxiety is a complex one, with each feeding into the other in a vicious cycle. 

In my work as a functional medicine practitioner, I’ve seen many people struggle with this exact issue. While it’s common to point the finger at stress or hormones triggering our anxiety, we often forget about a crucial piece of the puzzle: prioritizing sleep.

That’s right – your sleep habits might be the reason why you’re anxious all the time!

In this blog, I’m breaking everything down including:

  • The link between sleep and anxiety
  • A closer look at your sleep and wake cycle (aka the circadian rhythm)
  • The habits you’re doing that are affecting your anxiety
  • How to break free from the cycle once and for all!


The Science Behind the Connection

Think about the last time you had a sleepless night. You probably woke up the next day feeling like crap and noticed even the smallest things were setting off your anxiety. 

That’s because the relationship between sleep and anxiety is complex and bidirectional, aka they influence the other. Let’s take a closer look at how sleep affects anxiety:

  • Emotional Regulation:

    • When we sleep, our brains are hard at work processing emotions from the day. This emotional processing is crucial for managing stress and anxiety. But when we don’t get enough sleep, we don’t process it and instead bottle it up and leaves us feeling like we’re in “a glass case of emotion” (Ron Burgundy anyone?)
  • Amygdala Response:

    • Ever noticed that after a sleepless night, even the smallest things can set off your anxiety or leave you jumpy? That’s because sleep deprivation can rev up the amygdala, the part of your brain responsible for our fight-flight response. Lack of sleep puts us on edge and high alert. Then it feels like something’s about to go wrong at any moment.
  • Hormones: 

    • But it’s not just your brain that’s affected by lack of Zzz’s. Your body’s hormonal balance can also take a hit. Sleep deprivation messes with cortisol, the stress hormone, and melatonin, the sleep hormone. This hormonal imbalance can leave you feeling even more stressed and anxious.
  • Cognitive Function: 

    • Ever tried to tackle a problem, study or get work done after a late night? It’s like your brain is in a fog, making it harder to think clearly and rationally. That’s because our brains detox while we sleep. If you don’t sleep, it’s like all the garbage men going on strike and the trash piles up in front of your house for weeks. We clear that trash out every night when we get deep REM sleep and if we don’t then our brains feel like the sludge at the bottom of the dumpster.
  • Inflammation: 

    • Ever notice that when you’re running on empty, you not only experience more anxiety but also aches, pains or gut issues? That’s because chronic sleep deprivation can ramp up inflammation in your body, which messes with neurotransmitter function, digestion, hormones, metabolism and pain response.  Moral of the story? Sleep is GOAT (Greatest Of All Time).
  • Gut-Brain Axis: 

    • Did you know that your gut health could be affecting your anxiety? Recent studies show that the gut microbiome, the community of bacteria in your gut, plays a big role in anxiety since they help to make our neurotransmitters like serotonin, dopamine and GABA. And guess what disrupts this delicate balance? You guessed it—poor sleep. When you don’t get enough shut-eye, it can throw off your gut microbiome, leading to—you guessed it again—increased anxiety.



The circadian rhythm is our body’s internal 24-hour clock that regulates all kinds of bodily functions including energy levels, metabolism, and digestion.

It aligns with day and night, dictating when you feel alert and when you feel sleepy. When it’s out-of-sync (jet lag, night shift work, staying up too late, partying on the weekends), it can have a domino effect on every system in our bodies.


In the morning, for example, we should naturally have higher energy levels, better concentration, and faster reaction times. This is because when our eyes detect light it signals our body to produce cortisol.

Cortisol is one of our main ‘stress’ hormones that helps wake us up and prepares us to interact with our external environment.

As day turns into night, another hormone called melatonin kicks in. Melatonin makes us feel sleepy and signals to our body that it’s time to go to sleep. 

Cortisol and melatonin oppose each other. As cortisol naturally starts to decline later in the day and light exposure decreases, melatonin kicks in response to darkness, signaling it’s time for bed.

However, when cortisol is overactive and it’s naturally daily rhythm gets disrupted from things like:

  • long-term stress
  • chronic infections
  • mold toxicity
  • poor sleep
  • diet high in processed foods, sugar and caffeine
  • medications like corticosteroids
  • excessive exercise
  • smoking
  • excessive alcohol

It can cause things like weight gain, fatigue, anxiety, burnout, irritability and irregular blood sugar. 

Cortisol plays a crucial role in regulating our circadian rhythm. And because it affects so many systems in the body, regulating cortisol is essential for getting good sleep and maintaining overall health.


Just because your body has an internal clock doesn’t mean it’s timing is right. Our modern lives tend to be quite out of alignment with our natural clocks whether it’s staying up late scrolling, using too many lights at night, partying late on the weekends or not getting enough sunlight in the morning.

That’s right – your daily habits might be causing your circadian rhythm to be totally out of whack. And that misalignment is often what causes poor sleep and anxiety. Sound familiar?

As challenging as it might be to say no to those late-night invites, I urge you to implement a consistent sleep routine whenever possible, yes even on the weekends! The more we fight against our body’s natural rhythms, the more we start to experience side effects like lousy sleep, trouble concentrating, and anxiety ALL WEEK LONG.

Your circadian rhythm is more than just a sleep-wake cycle. It’s a fundamental biological process that influences nearly every aspect of your health. This internal clock regulates not only when you feel sleepy or alert but also impacts your metabolism, immune function, hormone levels, and even your mood.

Circadian rhythm can be disrupted by irregular sleep patterns, late-night exposure to screens, or shift work. This can lead to a range of health issues. Some examples include sleep disorders, mood disorders, metabolic problems, and even an increased risk of chronic diseases like diabetes and heart disease. 

Kacie in bed reading about how sleep and anxiety are linked


By now, you’re probably wondering how in sync YOUR circadian rhythm is. If you are anxious, exhausted upon waking, wired but tired, or have a hard time falling asleep at night, there’s a good chance that your clock needs some fine-tuning.

Here are some surprising things you might be doing that are disrupting it without you even knowing!

Using artificial light

Melatonin, the hormone that makes you feel sleepy, is produced by the pineal gland in the evening when exposed to darkness. That means being exposed to bright artificial lights during the evening can disrupt your melatonin production, and in turn, your sleep. Dim those lights if you gotta use ‘em, turn off the unnecessary ones and put your phone on night mode.

Not getting sunlight in the morning

As I explain in this blog, there’s more than just light at night that is affecting your sleep and anxiety. Our eyes have specialized receptors that detect light. When we go outside in the morning, this sends a signal to our brain that it’s daytime and it’s time to begin producing cortisol. This process keeps your circadian rhythm in sync. Lack of sun in the morning can contribute to crappy sleep at night and worse anxiety throughout the day! Go on a morning walk within an hour of waking or have your breakfast on the porch!

Eating too late in the evening

 Research suggests that the ideal window for eating is between 8:00 AM and 6:00 PM. This is because hormones like ghrelin and adiponectin, which play important roles in digestion, fullness, and metabolism, are at their peaks during this time. Aim for eating earlier in the day and eating smaller meals at night if you have to eat past 6pm.

Not eating in the morning

Just like you shouldn’t eat too late into the night, it’s important to “break your fast” when you wake up in the morning. This is because your body is ready to properly metabolize the food you eat. In this way it can use it as energy instead of storing it as fat. It’s important to eat something warm and savory within an hour or two of waking. This will help regulate blood sugar, avoiding those blood sugar spikes and crashes that feel a whole lot like anxiety.

Not getting enough exercise

Our bodies are designed to be active and move throughout the day, so it’s important to keep things moving! Go on walks and incorporate strength training. We experience optimal muscle strength and cardiovascular efficiency between 2-5 pm. BUT working out in the late afternoon and evening can also spike cortisol and keep us up at night. Morning exercise helps us keep our circadian rhythms synchronized and can also play a role in regulating anxiety.

Overall, you can break the chain between sleep and anxiety-

It can feel overwhelming to digest all this info and realize you’ve got some work to do. But I promise you, once you start working on regulating your circadian rhythm, your anxiety will improve drastically – and that’s only the beginning!

So many areas of health are related to our sleep, and if you want to make sustainable changes, you gotta put in the work!

Want more tips on how to regulate YOUR circadian rhythm and cortisol? Sign up to download our free guide, filled with checklists and practical tips, to help you synchronize with your circadian rhythm and improve your sleep, energy levels, and overall health.

Get your FREE Align Your Circadian Rhythm Guide by clicking here!