Tired but wired? Why you're exhausted but can't sleep (and what your cortisol could be trying to tell you)
You've had a long day.
You're physically exhausted, you've been looking forward to climbing into bed all day… and then it happens.
Your body is tired, but your brain suddenly decides it's the perfect time to replay awkward conversations from 10 years ago, worry about tomorrow's to-do list, or start planning your next holiday.
Sound familiar?
If you've ever wondered, "Why am I so tired but can't sleep?" you're certainly not alone. It's one of the most common sleep complaints, especially for women over 35.
While there isn't one single cause, one possible contributor is your body's main stress hormone – cortisol.
P.S you can access our cortisol fighting meal plan in our Zing Wellbeing app
What is cortisol?
Cortisol often gets labelled the "bad" hormone, but that's not actually true.
It's an essential hormone produced by your adrenal glands that helps regulate:
- Your sleep-wake cycle
- Blood sugar
- Blood pressure
- Metabolism
- Energy production
- Immune function
- Your body's response to stress
Without cortisol, you wouldn't be able to wake up in the morning or respond to everyday challenges.
The key isn't having no cortisol – it's having the right amount at the right time.
Cortisol should follow a natural daily rhythm
Your body is designed to follow a circadian rhythm.
Normally:
- Cortisol rises rapidly shortly after waking to help you feel alert.
- It gradually declines throughout the day.
- By bedtime, cortisol should be at its lowest, allowing melatonin to take over and help you fall asleep.
This natural rise and fall is one of the reasons we feel awake during the day and sleepy at night.
What happens when your cortisol rhythm is disrupted?
Modern life isn't exactly kind to our stress hormones.
Work pressures, financial stress, poor sleep, family responsibilities, illness, menopause and constant digital stimulation can all contribute to your nervous system staying switched on.
For some people, cortisol remains higher than normal into the evening.
Instead of feeling calm and sleepy, you may experience:
- Racing thoughts at bedtime
- Feeling "tired but wired"
- Difficulty falling asleep
- Waking between 2am and 4am
- Feeling alert during the night
- Restless sleep
- Waking feeling exhausted despite spending enough hours in bed
It's important to remember that these symptoms don't automatically mean your cortisol is high. Anxiety, menopause, caffeine, medications, poor sleep habits and other medical conditions can cause similar symptoms.
However, if stress has become a regular part of your life, cortisol may be one piece of the puzzle.
P.S you can access our cortisol fighting meal plan in our Zing Wellbeing app
Why women over 35 often notice this more
Many women find sleep becomes more difficult during perimenopause and menopause.
Declining oestrogen and progesterone can affect sleep quality directly while also making the body more sensitive to stress.
Hot flushes, night sweats and frequent waking can create a frustrating cycle:
Poor sleep increases stress.
Higher stress makes sleep more difficult.
The cycle repeats night after night.
Is waking at 3am always caused by high cortisol?
No.
Despite what you might read online, waking at 3am isn't a guaranteed sign of high cortisol.
It can also be linked to:
- Menopause
- Anxiety
- Sleep apnoea
- Alcohol
- Blood sugar fluctuations
- Needing the bathroom
- Environmental noise
- Certain medications
That said, chronic stress and elevated evening cortisol may contribute to early morning waking in some people.
How to naturally support a healthier cortisol rhythm
The good news is there are simple habits that can help support your body's natural sleep-wake cycle.
1. Get morning sunlight
Aim for 10-20 minutes of natural sunlight within the first hour of waking.
Morning light helps reinforce your body's circadian rhythm and can improve sleep later that night.
2. Move your body regularly
Exercise is one of the best ways to improve sleep quality and regulate stress hormones.
Strength training, walking, Pilates and yoga are all excellent options.
If possible, avoid very intense workouts immediately before bed.
3. Eat enough protein
Protein helps support stable blood sugar and keeps you feeling satisfied throughout the day.
Aim to include a quality source of protein at each meal.
4. Reduce caffeine later in the day
Caffeine can remain in your system for many hours.
If you're struggling with sleep, try avoiding coffee, energy drinks and strong tea after lunchtime.
5. Create an evening wind-down routine
Your brain needs time to recognise that the day is ending.
Try:
- Reading a book
- Gentle stretching
- Deep breathing
- Meditation
- Listening to calming music
- Taking a warm shower
Even 15-20 minutes can make a difference.
6. Limit screens before bed
Phones, tablets and laptops stimulate the brain and can delay melatonin production.
Try switching screens off at least an hour before bed where possible.
7. Keep a consistent wake-up time
Sleeping in on weekends might feel tempting, but waking at roughly the same time each day helps keep your internal body clock stable.
8. Manage stress during the day
Many people only think about relaxing when they get into bed.
Instead, build small moments of recovery throughout your day:
- Five minutes of deep breathing
- A short walk outside
- Journalling
- Time with friends
- Mindfulness
- Gentle stretching
Reducing stress throughout the day often makes it easier to switch off at night.
What about grounding?
You may have seen claims that grounding sheets or walking barefoot can dramatically lower cortisol.
While there are a handful of small studies suggesting grounding may influence stress or sleep, the evidence is still limited and isn't strong enough to recommend it as a proven treatment for insomnia or high cortisol.
If you enjoy spending time outdoors or walking barefoot on the grass, there's certainly no harm in doing so. Just be cautious of products that promise to "fix" high cortisol or cure poor sleep.
And if you are keen on trying grounding sheets we have bought sheets from a place called GROUNDING WELL and they are great! You can check them out here
When should you speak with your doctor?
Occasional poor sleep is completely normal.
However, if you're regularly struggling to fall asleep, waking multiple times every night, feeling exhausted despite sleeping, or your symptoms are affecting your daily life, it's worth discussing them with your healthcare professional.
Sleep problems can sometimes be linked to medical conditions that require assessment and treatment.
Feeling exhausted but unable to switch your brain off isn't something you should simply accept as normal.
While high evening cortisol isn't always the cause, chronic stress can disrupt your body's natural sleep rhythm and make quality sleep harder to achieve.
The good news is that small, consistent lifestyle habits - like getting morning sunlight, exercising regularly, eating enough protein, managing stress and creating a relaxing bedtime routine - can help support healthier sleep and a more balanced cortisol rhythm over time.
If you've been feeling tired but wired lately, your body may simply be asking for a little more recovery, consistency and care.
P.S you can access our cortisol fighting meal plan in our Zing Wellbeing app
