Lately, there’s been a surge of posts, reels, and wellness blogs claiming that “testing your cortisol” is the key to unlocking your health. You might have seen advice to “check your cortisol to see how stressed you are” or promises that balancing your cortisol will boost your energy, help you lose weight, or “reset your hormones.”
At ERH Associates, we love empowering people with accurate health information—so let’s break down what’s real, what’s hype, and when cortisol testing is genuinely useful.
What Social Media is Saying About Cortisol
Common claims floating around include:
- “If you feel tired, anxious, or burnt out, get your cortisol tested.”
- “A saliva cortisol panel will show if stress is making you sick.”
- “Balancing your cortisol will fix your weight, sleep, and mood.”
- “High cortisol means you’re in ‘adrenal fatigue.’” (see our separate article on adrenal fatigue here)
The problem? These ideas oversimplify how cortisol works, overstate what testing can tell you, and sometimes rely on non-standardised tests that can give misleading results.
What Cortisol Actually Tells Us
Cortisol is a hormone made by your adrenal glands. It plays a role in many important processes, including blood pressure regulation, metabolism, and immune function. It also rises and falls in a natural daily rhythm—highest in the morning, lowest at night.
A single cortisol reading isn’t a reliable measure of your overall stress load or your “wellness status.” Even if your cortisol level were a little high or low on a given day, it wouldn’t change the advice for managing stress and general health: optimise sleep, exercise regularly, eat well, connect socially, and address any underlying medical issues!
When Cortisol Testing Is Evidence-Based
1. Screening for Cortisol Excess (Cushing’s Syndrome)
Cushing’s Syndrome is a rare condition where the body makes too much cortisol, usually due to a benign tumour in the pituitary gland or adrenal glands.
Your doctor may suspect it if you have a combination of features such as:
- Purple stretch marks on the abdomen (wide and deeper in colour)
- Significant weight gain around the trunk with thinner arms and legs
- Very round, full face (previously called “moon face”)
- Very noticable fat pad at the upper back/neck (doesn’t always mean Cushings disease is present but in combination with other features suggests screening may be reasonable)
- Difficult to control or early-onset high blood pressure
- Skin thinning, easy bruising, or slow wound healing (again on it’s own doesn’t always mean Cushings disease is present, especially if obesity is not present, but in combination with other features may suggest screening is reasonable)
If your doctor suspects Cushing’s, the first-line screening test in New Zealand is a 1 mg overnight dexamethasone suppression test. In certain situations, your endocrinologist may also request a 24-hour urine cortisol test.
2. Screening for Cortisol Deficiency (Addison’s Disease)
Cortisol deficiency happens when the adrenal glands can’t produce enough cortisol—this is sometimes called Addison’s Disease when due to adrenal damage, and it is often autoimmune in origin.
Symptoms can include:
- Severe dizziness or fainting
- Unexplained fatigue
- Low blood pressure
- Unintentional weight loss (a non-specific feature on its own)
- Skin pigmentation changes (in some cases)
If Addison’s is suspected—particularly if you have other autoimmune conditions or a family history of them—your doctor may order an 8 am cortisol blood test. This timing matters because cortisol naturally peaks in the morning. The result may be affected by shift work or disrupted sleep patterns. If the level is low, further testing (such as an ACTH stimulation test) is undertaken.
Why “Routine Cortisol Testing” Isn’t Helpful
Outside of these medical scenarios, checking your cortisol “just to see how stressed you are” is not recommended. It’s not a reliable marker of your stress levels, and it doesn’t guide a specific treatment plan.
Whether your cortisol is slightly above or at the lower end of average, the approach to improving your well-being remains the same:
- Prioritise good sleep
- Engage in regular physical activity
- Eat a balanced diet
- Reduce alcohol and avoid smoking/vaping
- Nurture supportive social connections
- Manage psychological stress in ways that work for you
Bottom Line
Cortisol testing is a powerful tool—when it’s used for the right reasons. But as a general “wellness check” or “stress test,” it’s simply not supported by evidence. If you’re concerned about symptoms that could indicate Cushing’s Syndrome or Addison’s Disease, see your GP or endocrinologist for an assessment.
For everyone else, focus on the fundamentals of healthy living—you’ll be supporting your cortisol levels naturally without ever needing a lab form!
References:
- Nieman LK, et al. “The Diagnosis of Cushing’s Syndrome: An Endocrine Society Clinical Practice Guideline.” J Clin Endocrinol Metab 2008.
- Bornstein SR, et al. “Diagnosis and Treatment of Primary Adrenal Insufficiency: An Endocrine Society Clinical Practice Guideline.” J Clin Endocrinol Metab 2016.
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