Stress, fatigue and weight gain: Could high cortisol be the cause?

We explore how high cortisol levels could be the hidden culprit for you constantly feeling tired, overwhelmed and gaining weight—and what you can do about it.

You wake up tired even after a full night’s sleep. Your jeans are tighter around the waist even though you’ve been trying to eat better. You feel like you’re constantly running between school drop-offs, laundry, work, meals and endless to-do lists. You’re barely holding it together.

Sound familiar?

Chances are, you’re blaming yourself. But what if the real culprit is a little-known hormone that’s been quietly doing overtime in the background?

Let’s talk about cortisol, your body’s main stress hormone and it may be contributing to the exhaustion, overwhelm and changes in your body that you just can’t explain.

What is cortisol and why does it matter?

The hormone cortisol is produced by your adrenal glands, which sit just above your kidneys. Think of it as your built-in alarm system. It’s released in response to stressful situations, like when your toddler throws a tantrum in the grocery store or when you’re racing to make dinner after a long day.

In small doses, cortisol helps keep you alert, manages your blood sugar and even reduces inflammation. But when you’re under chronic stress, your cortisol levels stay high for a long time—and that’s when things start to go wrong.

While your body naturally produces cortisol to help you cope with stress, being exposed to high doses over a long time—especially during stressful situations—can disrupt your hormones and leave you feeling constantly tired, anxious and burnt out.

Everyday stress, real-life impact

Let’s be honest: Being a mum is a full-time job with no off-switch. It’s not just the big stresses like financial pressures or family health issues. It’s the little things, too—the sleepless nights, the multitasking, the mental load of remembering every dentist appointment, item on the grocery list and school project deadlines.

When these daily stressors pile up, your body doesn’t know the difference between a lion chasing you and a toddler melting down. It kicks into fight-or-flight mode, flooding your system with high cortisol.

Over long periods, this can lead to:

Weight gain, especially around the belly
Erratic or higher levels of blood glucose readings
Feeling wired but tired
Trouble sleeping
Increased blood pressure
Weakened immune system
Sugar cravings and blood sugar crashes
Feeling anxious, foggy or overwhelmed
Over-reactive stress response (having meltdowns about things that aren’t really that big of a deal)
Fight-or-flight response always being switched on

Becoming numb to stress

High levels of stress over time can lead to the development of a high tolerance for stress—a response that might seem adaptive at first but is actually quite harmful. As we repeatedly face stress, our bodies and minds begin to adjust, making stressful situations feel more familiar or even manageable. However, this adaptation masks the reality that we are still experiencing stress and it comes at a significant cost to our overall wellbeing.

As this tolerance builds, our baseline stress levels gradually rise. Situations that once felt overwhelming become something we simply power through. However, it doesn’t mean we’re avoiding the negative effects. Instead, our nervous systems become desensitised, making it harder to gauge when we’re reaching our limits. This can leave us especially vulnerable when bigger stressors hit—often without realising the full impact until we’re already overwhelmed.

Ultimately, a heightened tolerance for stress can lead to chronic stress and its many consequences: Burnout, anxiety and physical health issues like high blood pressure and weakened immunity. The body rarely gets a chance to recover, creating a cycle that’s difficult to break. Recognising this pattern and taking steps to lower stress levels is essential for protecting both mental and physical health and maintaining long-term balance.

The three types of stress

Stress manifests in different ways. Psychologists typically classify it into three main types:

1. Acute stress

This is the immediate reaction to a perceived threat. Your heart races, your muscles tense and you feel a rush of adrenaline. It’s your body’s way of preparing for action. Once the event passes, your body returns to baseline.

2. Episodic acute stress

Some people live in a near-constant state of acute stress due to high-pressure jobs, perfectionism or frequent crises. Over time, this pattern can lead to anxiety disorders and heart problems.

3. Chronic stress

When stress is prolonged—whether due to financial struggles, past trauma or long-term dissatisfaction—it becomes chronic. Chronic stress changes the brain’s structure, shrinking the hippocampus (which regulates emotions and memory) and enlarging the amygdala (which heightens fear responses).

The vicious cycle of high cortisol

When high cortisol levels linger, your body begins to feel the weight of it—literally and emotionally. Your sleep suffers, your hormones get thrown off balance and even your resting heart rate or blood pressure might creep up without warning. You may notice your waistline softening, not because you’re doing anything wrong, but because your body is trying to protect you. Storing fat—especially around your belly—is one of the ways it braces for ongoing stress.

It’s not just frustrating, it’s deeply exhausting. It can feel like your body is turning against you, even though you’re trying your best to get through the day. The truth is that even low levels of stress, constantly repeated daily, with no solutions appearing, will lead to a state of inner desperation.

The relentless pressure you’re carrying—emotionally, mentally, physically—isn’t just causing stress. It’s adding another layer: Worrying about how you feel, how you look and why you’re so tired all the time. That worry fuels even more stress and your high levels of cortisol respond by rising higher still. It becomes a loop that feels impossible to escape; a cycle that leaves you wondering if you’ll ever feel like yourself again.

Could it be something more?

In most cases, high cortisol is due to our excessively busy, hectic schedules. But in rare cases, extremely high cortisol can signal a condition like Cushing’s syndrome, which can involve a tumour or abnormality in the pituitary gland or adrenal cortex. Other signs may include thinning skin, muscle weakness and roundness in the face.

If your symptoms feel unmanageable, or if you’re noticing severe fatigue, rapid weight gain, or signs of high blood pressure or other health problems, talk to a trusted healthcare provider. You may need support with testing for cortisol levels, thyroid function or even hormones related to the adrenal glands and pituitary gland.

If you’re experiencing extreme symptoms, don’t hesitate to ask your doctor about a blood test to check your cortisol levels or rule out conditions like Cushing’s syndrome or Addison’s disease.

What can you do?

Getting better often doesn’t involve some massive treatment regime. Thankfully, there are gentle, practical steps you can take to support your body, reduce cortisol production and start feeling like yourself again.

1. Create buffer zones for your nervous system

It’s okay to take five minutes in the bathroom just to breathe. Build “pause moments” into your day. That might look like:

Sitting with a cup of tea before anyone wakes up
Playing calm music during dinner prep
Stepping outside barefoot for a moment of stillness

These micro-breaks help signal to your body that you’re safe and can help lower cortisol levels.

2. Nourish without obsessing

Skip the crash diets. When blood sugar is unstable, it triggers more stress. Focus on:

Protein and healthy fats at each meal
Eating regularly (don’t skip meals!)
Reducing processed sugar where you can

You don’t have to be perfect. But you do need to intentionally nourish your body so it can serve you well.

3. Gentle movement, not punishment

You don’t need a hardcore workout if your schedule is full and your energy is low. In fact, intense exercise at the wrong time can spike cortisol even more. Instead, try:

Walking outdoors
Stretching
Playing tag with the kids

Move because it feels good, not because you’re trying to “fix” your body.

4. Sleep is sacred

Easier said than done, right? But sleep is one of the most powerful tools for stress management. Try:

Going to bed 30 minutes earlier
Turning off screens an hour before bed
Lavender oil or a warm bath to wind down

It’s not just about the number of hours. It’s about quality rest that helps reset your stress hormone cycle.

5. Talk to someone

Whether it’s a therapist, your best friend or a mums’ group—sharing what you’re going through lifts the emotional weight. You don’t have to carry everything alone. High levels of unspoken emotion contribute to high cortisol secretion.

Healing takes time

Be patient with your body. You’ve been running on empty for a while, and healing from chronic stress won’t happen overnight. But with small, loving changes, you can shift from survival mode to a space of greater peace, energy and connection.

And most importantly? You’re not broken. You’re a woman who’s been holding everything together. It makes sense that your body has been crying out for relief. You’re not lazy. You’re not weak. You’re not doing it wrong.

You are carrying so much, and your body has been working overtime to help you keep going. Now it’s time to let it rest, to support it and to let healing happen—slowly, gently and with deep compassion.

So the next time you find yourself crying in the laundry or reaching for that third coffee by 10am, remember this: You’re not alone and it’s okay to ask for help. Your wellbeing matters, too.