Cortisol Levels: Symptoms of High and Low Cortisol and What to Know

Cortisol is a steroid hormone produced by the adrenal glands, released in response to signals from the hypothalamus and pituitary gland in what's known as the HPA axis (hypothalamic-pituitary-adrenal axis). It regulates blood sugar, metabolism, inflammation, blood pressure, and the sleep-wake cycle, and it rises in response to physical or psychological stress to mobilise energy quickly. Critically, cortisol isn't inherently harmful — it's essential for survival and normal daily function; the problems arise when levels stay elevated or suppressed for far longer than the body's stress response was designed to handle.

Cortisol follows a diurnal rhythm, meaning it naturally peaks in the morning and drops through the day — a single "normal" number doesn't exist without knowing the time it was measured.

Saliva and urine testing use different reference ranges to blood testing, so results should always be interpreted against the specific test type and its own lab reference range, not compared directly across testing methods.

Here are some symptoms you need to be on the look out for.

• Unexplained weight gain

If you notice slight weight gain around your face, abdomen or even upper back, then these are your signs to take the hint–you've got high cortisol levels.

• Thin, fragile skin

If you bump into bedside corners and bruises easily–consider it normal. It is only of concern if your bruises take time to heal.

• Persistent high blood pressure

You don't respond well to typical lifestyle changes and your blood pressure shoots up as a result.

• Muscle weakness

This is especially noticeable in the thighs and upper arms.

• Irregular or absent menstrual periods

Your periods are noticeably late or irregular.

• Difficulty falling asleep

Despite feeling physically exhausted, since chronically elevated evening cortisol interferes with the natural drop needed for sleep onset

• Increased susceptibility to infections

Due to cortisol's suppressive effect on immune function when chronically high

• Mood changes including anxiety

You experience extreme mood changes and feel anxious for no particular reason, and in some cases, symptoms resembling depression

• Purple or pink stretch marks

These marks are articularly wider than typical stretch marks, on the abdomen

Here are some common symptoms of low crotisol.

• Persistent fatigue that doesn't improve with rest or sleep

• Unintentional weight loss and reduced appetite

• Low blood pressure, sometimes causing dizziness on standing

• Salt cravings, linked to cortisol's role in regulating sodium balance

• Low blood sugar episodes, since cortisol normally helps maintain blood glucose between meals

• Darkening of the skin, particularly in skin folds, scars, and gum tissue — a specific marker of primary adrenal insufficiency (Addison's disease)

• Nausea, abdominal pain, or digestive disturbances without a clear cause

• Reduced ability to cope with physical stress, including prolonged recovery from minor illness or injury

Abnormal cortisol levels are due to multiple reasons. Here are some of them.

Long-term stress doesn't just mean "high cortisol" — that's the common assumption, but it's not quite right. Often, the whole daily rhythm flattens instead: the morning peak barely rises, and the evening drop doesn't fall as it should.

Caused by prolonged exposure to excess cortisol — either from a tumour affecting the pituitary or adrenal glands, or from long-term use of corticosteroid medications. Interestingly, it's the medication-related cases that are far more common than tumours.

Caused by prolonged excess cortisol — either from a pituitary or adrenal tumour, or long-term corticosteroid use, with the latter far more common.

One of the most common causes of abnormal cortisol isn't a hidden condition — it's long-term corticosteroid use for things like asthma or arthritis. Stopping suddenly can even trigger low-cortisol symptoms, since the adrenal glands need time to resume normal function after being suppressed for so long.

Irregular sleep schedules and chronic sleep deprivation disrupt the timing of the cortisol awakening response specifically, which is often measurable even before someone reports feeling unusually stressed.

Less common but clinically significant, tumours affecting either gland can push cortisol production in either direction depending on the tumour's specific effect on the HPA axis.

Here are ways to easy ways cortisol levels

• Morning blood test: The standard first check, timed to catch cortisol's natural peak — testing at the wrong time can skew results.
• Late-night salivary cortisol : Checks whether cortisol drops properly at night — a key marker for Cushing's syndrome.
• 24-hour urinary free cortisol : Measures total output across a full day, useful for spotting sustained overproduction.
• ACTH stimulation test: Assesses how well the adrenal glands respond to a synthetic trigger hormone — used when adrenal insufficiency is suspected.
• Dexamethasone suppression test : Checks whether cortisol production suppresses correctly after a steroid dose — key for diagnosing Cushing's syndrome.
• Hair cortisol analysis: A newer method reflecting average cortisol exposure over months rather than a single day — useful in research and some long-term clinical cases.

Stress free means normal cortisol levels. Here's how to calm your mind amidst daily life chaos.

• Keep a consistent sleep and wake time. The cortisol awakening response is built around regularity, not just clocking enough hours. Waking at wildly different times each day throws that rhythm off, even if you're technically well-rested.
• Get natural light within the first hour of waking. This is what tells your body it's actually morning, helping anchor that natural cortisol peak to the right part of the day.
• Hold off on caffeine for the first two to three hours after waking. Your cortisol is already climbing naturally during this window, and caffeine on top of it can push levels higher than they'd otherwise go on their own.
• Make exercise a regular, moderate habit. Movement helps — but go too hard, too often, without proper recovery, and you can end up chronically raising cortisol rather than easing it.
• Try structured relaxation techniques, like paced breathing or progressive muscle relaxation. These have a genuinely measurable effect on lowering cortisol in the moment — more so than simply resting passively.
• Keep blood sugar stable with regular meals. Big swings in blood sugar prompt the body to release more cortisol just to bring glucose back into balance.
• Cut back on screens and stimulating activity late in the evening. This is often what quietly interferes with cortisol's natural decline at night, making it harder to wind down.

One bad night's sleep or a stressful week isn't your cortisol malfunctioning — that's just life. What's worth noticing is when several symptoms from the same list, high or low, start showing up together and sticking around.

A few things I'd flag straightaway: sudden weight redistribution, new stretch marks, unexplained skin darkening, or light-headedness with salt cravings and low blood pressure. Any one alone might be nothing — together, they're worth a proper conversation.

And don't try to self-diagnose from a list. Cortisol issues are confirmed with testing, not guesswork — if this sounds like you, it's worth booking that appointment.

Your body's been keeping time long before clocks existed. Cortisol rises each morning to wake you up, then steps back by evening — not high, not low, just on time.

Somewhere along the way it got recast as the villain, a number to chase down. But a hormone built to fluctuate can't be judged by one reading — only by whether it's still keeping the beat.

Feeling wired at night or foggy each morning? That's usually a drifted rhythm, not a crisis — fixed with sleep, morning light, and regular meals, not a supplement.

But sudden weight shifts, unexplained stretch marks, dizziness, or salt cravings? That's a different conversation — one for a doctor, not a search bar at 1am.