
Biological age
Find out if your body is aging faster or slower than your actual age — and see how you rank against the general population.
39
Biological age
44
Actual age
4.2
Years younger

Cortisol Total Test (Blood): What It Measures and How to Read Your Result. It measures total cortisol in your blood at a specific time to assess adrenal hormone output; order through Vitals Vault and test at a nearby Quest lab.
Total cortisol is a snapshot of how much cortisol is circulating in your blood at the moment your sample is drawn. Cortisol is your main “stress hormone,” but it also helps regulate blood sugar, blood pressure, inflammation, and how you respond to illness. Because cortisol follows a strong daily rhythm, the same person can have a “normal” value in the morning and a much lower value later in the day. That is why the timing of your blood draw and your medications matter as much as the number itself. A total cortisol test can be useful when you are investigating fatigue, dizziness, low blood pressure, unexplained weight changes, or when you and your clinician are monitoring steroid therapy. The goal is not to self-diagnose from one result, but to use the data to decide whether follow-up testing or a different type of cortisol test is needed.
What to expect before and at your draw.
Sample Type
Blood
Collection Method
In person at a Quest Diagnostics location
Age
18+
This order includes the lab markers used for Cortisol.
Cortisol, Total
Included in this Quest Diagnostics order and reported in your Vitals Vault account.
Order Cortisol online.
Visit a Quest Diagnostics location near you for your blood draw. Appointments can be scheduled after checkout.
View easy-to-read results in your Vitals Vault account, with trends and clinician-guided follow-up when available.
Included with every package
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Find out if your body is aging faster or slower than your actual age — and see how you rank against the general population.
39
Biological age
44
Actual age
4.2
Years younger

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Order online
Add Cortisol to your cart and check out. No doctor referral is required.
Visit a Quest lab
Provide your blood sample at a Quest Diagnostics location. Appointments can be scheduled after checkout.
Review in Vitals Vault
Results typically arrive in about a week and stay in your Vitals Vault account for trends and follow-up.
No special preparation is usually needed unless noted at checkout.
This order includes the lab markers used for Cortisol and reported in your Vitals Vault account.
Results
About 1 week after your draw
HSA/FSA
Accepted
Who takes it
Must be taken by the purchaser
Preparation
No special preparation needed unless noted at checkout.
It measures total cortisol in your blood at a specific time to assess adrenal hormone output; order through Vitals Vault and test at a nearby Quest lab.
Total cortisol is a snapshot of how much cortisol is circulating in your blood at the moment your sample is drawn. Cortisol is your main “stress hormone,” but it also helps regulate blood sugar, blood pressure, inflammation, and how you respond to illness.
Because cortisol follows a strong daily rhythm, the same person can have a “normal” value in the morning and a much lower value later in the day. That is why the timing of your blood draw and your medications matter as much as the number itself.
A total cortisol test can be useful when you are investigating fatigue, dizziness, low blood pressure, unexplained weight changes, or when you and your clinician are monitoring steroid therapy. The goal is not to self-diagnose from one result, but to use the data to decide whether follow-up testing or a different type of cortisol test is needed.
You may consider a total cortisol test if you have symptoms that could fit either too little or too much cortisol and you want an objective starting point. People often look at cortisol when fatigue feels out of proportion to sleep, when you feel “wired but tired,” or when you have lightheadedness, nausea, or low appetite that does not have a clear explanation.
This test is also commonly used when there is a specific clinical question, such as possible adrenal insufficiency (low cortisol production), possible cortisol excess, or when you are taking glucocorticoid medications (like prednisone, hydrocortisone, dexamethasone, or steroid injections) and need help understanding how therapy may be affecting your adrenal axis.
Timing is a big part of whether this test will answer your question. If your draw is not done at the right time for the question being asked (often around 8 a.m. for “morning cortisol”), a normal result can still be misleading. If your symptoms suggest a rhythm problem rather than an absolute cortisol problem, a different approach (repeat morning cortisol, late-night testing, or multi-time-point saliva/urine strategies) may be more informative.
Use this result as one piece of clinician-directed care. A single cortisol value rarely confirms a diagnosis on its own, but it can guide what to do next.
Cortisol is measured in a CLIA-certified laboratory; results should be interpreted with collection time, reference ranges, and clinical context rather than used as a standalone diagnosis.
Lab testing
from $22.99 at Quest Diagnostics
About 1 week
Schedule online — results typically within a week
Clear next steps
Guidance included, with follow-up care available
HSA / FSA
Eligible for pre-tax health spending accounts
Vitals Vault lets you order a Cortisol Total lab test directly, then complete your blood draw at a nearby Quest location. This is helpful when you want a clear baseline, need a repeat morning cortisol for comparison, or are tracking changes over time.
After your results post, you can use PocketMD to ask practical questions like whether your draw time makes the result interpretable, which medications can skew cortisol, and what companion labs are commonly paired with cortisol when symptoms persist.
If your situation suggests broader adrenal-axis or stress-physiology testing, you can also use your cortisol result to decide whether a more comprehensive panel is worth adding, rather than guessing up front.
You will get a lab-grade result you can share with your clinician, along with a clearer plan for what to repeat, what to add, and what not to over-interpret.
Cortisol is a steroid hormone made by your adrenal glands. It helps your body respond to stress, maintain blood pressure, regulate glucose availability, and modulate inflammation.
“Total cortisol” means the test measures both the cortisol that is bound to proteins in your blood (mostly cortisol-binding globulin, CBG) and the smaller fraction that is unbound (“free”) and biologically active. Because most cortisol is protein-bound, changes in binding proteins can change total cortisol even when free cortisol is unchanged.
Your brain and adrenal glands regulate cortisol through the HPA axis (hypothalamic–pituitary–adrenal axis). ACTH (adrenocorticotropic hormone) from the pituitary signals the adrenals to produce cortisol, and cortisol then feeds back to the brain to keep the system in balance.
Cortisol also follows a diurnal rhythm: it is usually highest in the early morning, then gradually declines through the day, reaching its lowest point near midnight. That rhythm is why the collection time printed on your report is not a minor detail—it is central to interpretation.
Total cortisol is often the first-line blood test because it is widely available and standardized. Free cortisol is sometimes assessed through saliva or urine testing, which can be useful when binding proteins are altered (for example, pregnancy or estrogen therapy) or when the clinical question is about cortisol rhythm or cortisol excess.
A morning draw (often around 7–9 a.m.) is commonly used when evaluating possible adrenal insufficiency because that is when cortisol should be near its daily peak. If you draw later in the day, a lower value may be normal for that time, and a “normal” value could still be inappropriate if symptoms suggest the morning peak is blunted.
A low total cortisol result can happen when your adrenal glands are not producing enough cortisol, when ACTH signaling is low, or when steroid medications have suppressed your natural production. It can also be seen if the blood draw was taken later in the day, when cortisol is expected to be lower. If your symptoms include significant fatigue, dizziness on standing, low blood pressure, or unintentional weight loss, a low morning cortisol often leads to confirmatory testing rather than immediate conclusions. Your clinician may consider repeat morning cortisol, ACTH, electrolytes, or dynamic testing depending on severity and context.
An in-range result means your total cortisol at that specific draw time falls within the lab’s reference interval. This is reassuring, but it does not always rule out a cortisol-related problem if the sample timing was off, if you are on medications that affect cortisol, or if your symptoms point to rhythm disruption rather than absolute deficiency or excess. If you are tracking recovery from steroid use, consistency matters: repeating the test at the same time of day is often more useful than comparing two differently timed draws. When symptoms persist, pairing cortisol with related markers can help you avoid over-focusing on a single number.
A high total cortisol result can reflect acute stress, poor sleep, pain, illness, intense exercise, or certain medications, especially when the draw is done later than intended or during a stressful event. Persistently high results—particularly when paired with symptoms like easy bruising, muscle weakness, new or worsening high blood pressure, or high blood sugar—may prompt a more targeted evaluation for cortisol excess. Because total cortisol is influenced by binding proteins, some people have higher total cortisol without a true increase in free cortisol. Follow-up testing is usually about confirming a pattern, not reacting to a single elevated value.
Collection time is the biggest driver because cortisol changes substantially across the day. Medications can also shift results, including oral, injected, inhaled, or topical steroids; estrogen-containing therapies can raise binding proteins and increase total cortisol; and some anti-seizure drugs can alter metabolism. Pregnancy, thyroid status, liver disease, and changes in cortisol-binding globulin can move total cortisol without the same change in free cortisol. Sleep deprivation, shift work, acute illness, and recent strenuous exercise can all raise cortisol transiently, so your “real baseline” may require a calmer, well-timed repeat.
Total cortisol includes both protein-bound cortisol and free (unbound) cortisol in your blood. Free cortisol is the active fraction and is often assessed with saliva or urine methods when binding proteins may be altered or when rhythm/excess is the main question.
It depends on the clinical question, but many evaluations for low cortisol start with a morning draw (often around 7–9 a.m.) because cortisol should be near its daily peak. If you test at a different time, your result may be normal for that time yet not answer the question you are trying to solve.
Fasting is not always required for cortisol itself, but your clinician or the lab may recommend fasting if cortisol is being ordered with other tests that do require fasting. More important than fasting is consistent timing, typical sleep the night before, and noting medications.
Yes. Acute stress, anxiety about the blood draw, pain, illness, and sleep deprivation can raise cortisol temporarily. If your result is high and the circumstances were unusual, repeating the test under more typical conditions is often part of a sensible follow-up plan.
They can, and this is one of the most common reasons cortisol results are confusing. Glucocorticoids can suppress your body’s own cortisol production, and some forms can cross-react with certain assays. Always list oral, inhaled, injected, topical, and nasal steroids, plus the timing of your last dose.
A total cortisol test can show whether your cortisol is low, in-range, or high at a specific time, but it does not diagnose a catch-all fatigue condition. If you are exhausted, the most useful approach is to interpret cortisol alongside timing, symptoms, medications, and sometimes follow-up tests that evaluate the adrenal axis more directly.
Common companions include ACTH (to help localize whether the signal to the adrenals is appropriate), DHEA-S (another adrenal hormone that can add context), and basic labs like electrolytes and glucose. If cortisol excess is a concern, clinicians often use specialized tests that assess cortisol patterns rather than a single daytime value.
Purchase online through Vitals Vault. A licensed clinician reviews and approves your order, then you receive a digital requisition for a Quest Diagnostics blood draw.
Samples are collected in person at Quest Diagnostics locations nationwide. After checkout you can schedule your visit at a convenient site.
Most results are ready about a week after your draw. You can view them securely in your Vitals Vault account.
No separate referral appointment is required. Clinician review is included in the online order flow.
Yes. Eligible HSA/FSA cards can be used at checkout for qualifying lab orders.
Results are available in your secure Vitals Vault account. You control who you share them with, subject to applicable law.
Blood glucose shows the amount of sugar in your blood at a single moment. A1c (hemoglobin A1c) estimates your average blood sugar over roughly the past 8–12 weeks. Comparing them helps explain whether your long-term average lines up with your fasting glucose on draw day.
It helps you understand how this marker fits into your broader metabolic picture, with results tracked in your Vitals Vault account.
Elevated values can signal higher metabolic risk. Many people start with nutrition, activity, sleep, and weight management, then retest and review results with a clinician. This test is educational and does not replace medical advice or diagnosis.
Your sample is processed at CLIA-certified Quest Diagnostics laboratories. Results should still be interpreted with a qualified clinician alongside your history, symptoms, and other labs.
Consumer-initiated testing through Vitals Vault is limited to adults 18+ so ordering and interpretation stay aligned with clinical best practices for this channel.