Cortisol Levels: Causes, Symptoms and How to Improve Them
Cortisol Levels: Causes, Symptoms and How to Improve Them
Cortisol is often called the 'stress hormone', but it's involved in far more than just your stress response. It's a very important hormone which helps to regulate your sleep cycle, metabolism, blood pressure, and immune system. When cortisol becomes a problem, it isn't necessarily the hormone itself causing the issue, but what happens when it stays raised for too long, or when levels drop too low.
This guide covers the causes of off-balance cortisol levels, the warning signs that might indicate something's off, and some tips from our clinicians on how to bring your cortisol levels back into a healthy range.
Three key takeaways
Cortisol is essential, not just a stress hormone. The problem is when it stays raised or too low.
Symptoms of high and low cortisol overlap with other conditions, so it's worth seeing a doctor rather than self-diagnosing.
Sleep, activity, and cutting back caffeine and alcohol work better than any supplement or quick fix.
What is cortisol?
Cortisol is a hormone made by the adrenal glands. Our clinicians describe it as the body's alarm system: it rises when we face a stressful situation, helping us to stay alert and respond, then falls back to normal once you're no longer in that situation. A healthy cortisol response is meant to be temporary.
Problems start when you're constantly under stress, or when something else keeps your cortisol levels raised over a longer period of time. Instead of the usual peaks and troughs, the body stays in a heightened state of alert, which can affect your sleep, mood, appetite, and energy levels over time.
High cortisol vs low cortisol at a glance
High cortisol
Low cortisol
What it means
Cortisol stays raised for a prolonged period instead of rising and falling as normal
The adrenal glands don't produce enough cortisol
Common causes
Ongoing stress, poor sleep, overtraining, some steroid medicines
Addison's disease, adrenal insufficiency, some medication changes
Typical signs
Poor sleep, fatigue, anxiety, weight gain, sugar cravings, headaches, getting ill more often
Fatigue, unexplained weight loss, low blood pressure, dizziness, salt cravings
Next step
Lifestyle changes first, see a GP if symptoms persist or worsen
See a GP, low cortisol needs proper diagnosis and management
What causes high cortisol levels?
There's rarely a single cause of high cortisol – it's usually down to a combination of factors. One of the most common is ongoing psychological stress, which can be due to work pressure, financial worries, caring for someone else, or a life event that you're finding it difficult to deal with.
Not getting enough sleep, or waking up throughout the night, is another major factor, as disrupted sleep can interfere with the body's natural cortisol rhythm.
Other things that can raise cortisol include:
drinking too much caffeine
training too hard or too often without giving your body enough recovery time
working long or irregular hours consistently
taking certain medicines, particularly long-term steroid medicines like prednisolone
In rarer cases, persistently high cortisol can be caused by a medical condition, like Cushing's syndrome, a hormonal disorder, or a tumour pressing on a hormone-producing gland. Because of this, symptoms should always be looked at alongside your overall health and medical history, rather than on their own.
What are the symptoms of high cortisol?
High cortisol can affect the body and mind in several ways. Here are some of the most common things to look out for:
Difficulty sleeping despite feeling exhausted
One of the earliest signs that people notice is struggling to switch off at night. You may be:
Cortisol naturally helps to regulate alertness, so raised levels can interfere with the body's normal sleep cycle.
Persistent tiredness that doesn't get better with rest
This might seem contradictory, but high cortisol can leave you feeling constantly drained. When the body’s under stress over a long period of time, it uses a lot of energy, so many people feel physically tired and mentally exhausted despite sleeping or resting more. This tiredness can often be mistaken for simply being busy or overworked.
Increased anxiety, irritability, or feeling on edge
When, instead of fluctuating up and down, your cortisol stays high, it can affect your mood and emotional wellbeing. You might become more reactive to everyday stress, feel more anxious or restless, or notice that you have a shorter temper than usual. These changes tend to develop gradually, which can make them easy to miss.
Weight gain around your middle
Long-term raised cortisol has been linked to changes in how the body stores fat, particularly around the midsection. You may notice weight gain despite no real change in your diet or activity levels.
Many factors influence body weight, but a change in your body composition can sometimes be a clue that hormones are involved. Menopause can also cause elevated cortisol levels, which, when combined with falling levels of oestrogen, can cause weight gain around your abdomen.
Cravings for sugary or high-calorie foods
When you're stressed, the body naturally looks for quick sources of energy. Raised cortisol can increase appetite and food cravings, particularly for foods high in sugar, fat or refined carbohydrates. This is often put down to a lack of willpower, when the biological drivers behind your cravings are more complicated.
Frequent headaches and muscle tension
Headaches, jaw clenching, neck pain, and shoulder tension are often blamed on posture or screen time, but chronic stress can play a role too. Muscles tend to stay partly contracted during periods of prolonged stress, leading to ongoing aches and tension.
Reduced immunity and getting ill more often
High cortisol can affect your immune system's function over time. You may notice you seem to catch every cold going round, take longer to recover from minor illnesses, or have more frequent flare-ups of existing health conditions. Because this develops gradually, it's often one of the signs that people don't immediately connect with chronic stress.
What causes low cortisol levels?
Low cortisol happens when your adrenal glands don't produce enough of the hormone, most often due to adrenal insufficiency or Addison's disease. Left untreated, this can lead to an adrenal crisis, a medical emergency that causes:
severe weakness
very low blood pressure
fainting
Anyone with symptoms of low cortisol should see a GP rather than trying to manage it alone.
What are the most common low cortisol symptoms?
Symptoms of low cortisol can be subtle at first and easy to put down to other things. Common ones include:
persistent fatigue
unexplained weight loss
low blood pressure and dizziness, especially on standing up
craving salty foods
low mood
darkening of the skin
When should you see a doctor, and how is high cortisol tested?
If you notice persistent or worsening weight changes, high blood pressure, severe fatigue, or significant mood changes, it's sensible to speak to a healthcare professional.
'Many of the symptoms attributed to cortisol can also be linked to conditions like thyroid disorders, anxiety, depression, sleep disorders, menopause or nutritional deficiencies. Self-diagnosing based on symptoms alone can therefore be misleading.'
If a doctor suspects a cortisol disorder, they might arrange for you to come in for specialist testing. This can include a blood test, a urine test, or a saliva test taken at specific times of day, to assess your cortisol production and check whether your body's normal hormonal rhythm is working as it should.
How can you reduce cortisol naturally?
The first step is usually to focus on your daily routine and basic health needs rather than searching for a quick fix. Lifestyle steps that you can take to manage your cortisol levels include:
good sleep habits
regular physical activity
stress management techniques
staying socially connected
limiting caffeine or alcohol
These all have a stronger evidence base than many products marketed as 'cortisol lowering'.
It's the same story with the cortisol tests you can buy online. They can be hard to make sense of without your full medical context. An abnormal result doesn't always mean something's wrong, and a normal one doesn't always explain how you're feeling. If you're worried about your cortisol levels, a chat with a GP or pharmacist will always tell you more than an at-home kit.
'People should also be careful of social media trends that suggest a single cortisol supplement, cortisol detox, drink or routine can dramatically reduce cortisol levels. Hormones are complex, and there's rarely one simple solution.'
If you're worried about your cortisol, it's not something to manage alone, but it's also not something to panic about. If you recognise the signs above, start with the foundations:
If symptoms persist, get worse, or you would simply like some guidance, our clinicians are here for you. Speak to one of our pharmacists for advice on general wellbeing support, or book a GP appointment if you think you need a test.
Frequently asked questions about cortisol
Can you take supplements to reduce cortisol?
Some supplements may support general wellbeing and stress resilience, but none have been proven to lower cortisol on their own. Our clinicians recommend focusing on lifestyle solutions first and speaking to a pharmacist before you start taking any new supplement.
What is a cortisol detox diet?
There's no medically recognised 'cortisol detox diet'. This is a social media trend, and not an evidence-based approach to stabilising cortisol. A balanced diet, good sleep, and regular activity do more for cortisol levels than any detox plan.
Can you take a cortisol blood test to check your levels?
Yes, but at-home cortisol tests can be hard to interpret without a doctor, and results don't always match up with symptoms. A GP can arrange proper testing alongside an assessment of your wider health.
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