Cortisol Test: What Your Stress Hormone Results Mean

What Is a Cortisol Test?

A cortisol test measures the level of cortisol, a steroid hormone made by the adrenal glands, in blood, urine, or saliva. Cortisol helps control blood sugar, blood pressure, inflammation, and the response to stress. Blood testing is most common, while 24-hour urine or late-night saliva samples are used for specific diagnostic questions.

Cortisol follows a strong daily rhythm, peaking in the early morning and falling to its lowest around midnight. That rhythm is why the time of collection matters as much as the number itself. This is educational information, not medical advice.

Why a Cortisol Test Is Ordered

• Weight gain, stretch marks, or high blood pressure suggesting excess cortisol
• Fatigue, weight loss, or low blood pressure suggesting cortisol deficiency
• Known or suspected adrenal or pituitary disorders
• Monitoring steroid medication effects on the adrenal glands
• Workup of abnormal blood sugar or potassium with no clear cause

Cortisol is often ordered with ACTH, the pituitary hormone that drives cortisol production, so the source of a problem can be located.

Normal Cortisol Range

Ranges vary by laboratory and sample type. Typical blood reference points are:

A healthy pattern shows a clear morning peak and evening fall. A flat pattern with no evening drop can be as informative as any single number.

What High Cortisol Means

Persistently high cortisol may indicate Cushing syndrome, caused by steroid medications, a pituitary tumor, an adrenal tumor, or excess ACTH from another source. Signs can include central weight gain, a rounded face, easy bruising, high blood pressure, and high blood sugar.

Temporary rises are common with acute illness, surgery, severe stress, pregnancy, and intense exercise. That is why abnormal results are usually confirmed with repeat or timed testing, such as late-night saliva or a dexamethasone suppression test ordered by a clinician.

What Low Cortisol Means

Low cortisol may indicate adrenal insufficiency. In primary adrenal insufficiency (Addison disease), the adrenal glands themselves fail, and ACTH is usually high. In secondary insufficiency, the pituitary makes too little ACTH, often after long-term steroid use or pituitary disease.

Symptoms can include fatigue, weight loss, nausea, dizziness on standing, and salt craving. Because an adrenal crisis can be dangerous, low results with symptoms deserve prompt clinical follow-up rather than watchful waiting.

How to Order a Cortisol Test and Where to Get Tested

Cortisol testing is available through a clinician or through direct-access lab testing, where you order online and visit a local collection site. Morning draws are usually scheduled between 6 and 8 a.m., and some orders add an afternoon draw so the daily pattern can be compared.

Tell the lab about steroid creams, inhalers, injections, or pills, since these are the most common cause of unexpected results. An ACTH add-on helps show whether an abnormal cortisol starts at the adrenals or the pituitary.

How Much Does a Cortisol Test Cost?

Direct-access blood cortisol testing commonly costs between about $50 and $100. AM and PM paired testing usually runs about $90 to $160, and adding ACTH raises the total further. Saliva and 24-hour urine cortisol panels are priced in a similar range.

Insurance often covers cortisol testing when symptoms or a clinician order support it. For direct-access orders, confirm whether the collection fee is included in the quoted price.

Factors That Can Shift Cortisol Results

Cortisol reacts to almost everything. A stressful commute, a poor night of sleep, a recent workout, pregnancy, and even the anxiety of the blood draw itself can raise the number. Estrogen in birth control pills raises the bound fraction measured by total cortisol assays, which is one reason unexpected highs get repeated.

Shift workers and people with irregular sleep often show a flattened daily rhythm that mimics disease patterns. For the cleanest result, keep a normal sleep schedule for several days before testing, arrive calm and on time, and list every steroid product you use, including creams and inhalers.

Confirming an Abnormal Cortisol Result

A single abnormal cortisol rarely settles the question. Clinicians typically confirm highs with late night saliva testing or a low dose dexamethasone suppression test, and confirm lows with morning cortisol plus ACTH or a stimulation test. These follow ups need a clinician order, since they involve timed collections and prescription drugs.