Introduction
The cortisol level in the blood, urine, or saliva can be measured through a cortisol test to determine if it falls within the normal range. Cortisol is a hormone that impacts nearly all of the body's organs and tissues. It aids in the following:
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Managing stress (cortisol is often referred to as the "stress hormone").
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Lowering inflammation.
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Balancing blood sugar and metabolism (the process by which the body converts food into energy).
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Regulating blood pressure.
The adrenal glands, located above the kidneys, produce cortisol. The pituitary gland, located in the brain, secretes a hormone that instructs the adrenal glands on how much cortisol to produce. Abnormal cortisol levels may indicate an adrenal gland ailment, a pituitary gland issue, or a tumor that generates cortisol. If a person consumes high doses of particular steroid medications, such as Prednisone, over an extended period, they may also experience elevated cortisol levels. Conversely, if they abruptly stop taking the medication, cortisol levels may decrease. Untreated, imbalanced cortisol levels can lead to severe consequences. Other names for cortisol include urinary cortisol, salivary cortisol, free cortisol, blood cortisol, and plasma cortisol.
What Is Cortisol?
Cortisol is a hormone synthesized by the adrenal glands. It is also called the "stress hormone" because it is released in response to stress and plays an important role in the body. Cortisol helps to regulate blood sugar levels, blood pressure, immune function, and the body's response to inflammation. It also helps in the metabolism of fat, protein, and carbohydrates. Cortisol levels change during the day and are affected by stress, physical activity, and sleep.
What Is the Use of Cortisol Test?
A cortisol test aids in identifying medical issues that trigger abnormal cortisol levels, including disorders affecting the adrenal glands such as:
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Cushing's Syndrome: A condition where the body has excessive cortisol for an extended duration.
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Addison's Disease: A disorder where the adrenal glands are damaged and cannot generate sufficient cortisol.
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Secondary Adrenal Insufficiency: A condition where the adrenal glands do not produce adequate cortisol because the pituitary gland is not functioning correctly.
Furthermore, cortisol testing is employed to keep track of treatment for these ailments.
What Is the Procedure to Perform Cortisol Test?
A cortisol test involves taking a blood sample at a laboratory, but it can also be conducted on urine or saliva samples collected at home. Since cortisol levels naturally fluctuate throughout the day, healthcare providers may request multiple tests of varying types to gain further insights into cortisol levels.
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Blood Test: In a cortisol test, the doctor will draw a small blood sample from a vein in the arm using a tiny needle. This process typically lasts for under five minutes and might lead to mild discomfort during needle insertion or removal.
Cortisol testing often involves taking two blood samples, typically in the morning when cortisol levels are highest and again around 4 p.m. when levels are at their lowest.
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Urine Test: The healthcare provider may request a "24-hour urine sample test," where the patient will be required to collect all the urine for a 24-hour period. Patients will be provided with a special container and detailed instructions on how to collect and store the urine sample. The provider will inform the patient about the start time for the test, and the following steps are typically involved:
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First, urinate as usual in the toilet and do not collect this urine. Remember to write down the time of urination.
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Over the next 24 hours, collect all the urine in the provided container.
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During the collection period, store the urine container in a refrigerator or cooler with ice.
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After 24 hours, try to urinate again as the last urine collection for the test.
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Finally, return the container with the urine to the provider's office or laboratory as directed.
In some instances, a urine test for cortisol may only require one urine sample collected in the morning.
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Saliva Test: A saliva test is often conducted using a kit that can be used to collect a saliva sample at home. The healthcare provider will instruct the appropriate time to collect the sample, which is typically at night when cortisol levels are naturally lower.
Most kits come with a swab and a container for storage. It is essential to adhere to the instructions provided with the kit, which typically include the following steps:
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Avoid eating, drinking, brushing, or flossing the teeth for at least half an hour before the test.
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Wash and dry one’s hands.
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Open the tube containing the swab and allow it to fall into the mouth without using the hands.
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Roll the swab in the mouth or place it under the tongue for around two minutes until it is saturated with saliva.
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Return the swab into the tube without making contact and securely seal the tube.
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Label the tube with the time of collecting the sample.
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Take the saliva sample to the lab or to the doctor's office the next day as directed.
Is Any Preparation Required Before Cortisol Test?
The steps that need to be taken to prepare for the cortisol test will vary based on the type of test. Follow all the instructions given by the healthcare provider carefully. Since stress can increase cortisol levels, the provider may advise a patient to rest before the test. If a person is having a blood test, they will need to schedule two appointments at different times of the day. Before a saliva test, the patient may need to discontinue certain medications. Inform the provider about all medications, including any topical creams. Only discontinue medication after consulting with the provider first.
What Do the Cortisol Test Results Mean?
A cortisol test alone is insufficient to determine the underlying cause of abnormal cortisol levels. If the cortisol levels are found to be abnormal, further testing is typically necessary to identify the underlying issue.
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High Cortisol Level: Elevated cortisol levels may indicate the presence of Cushing's syndrome, which can result from various factors, including prolonged usage of high-dose steroid medications to treat conditions like lupus, asthma, and rheumatoid arthritis. Additionally, it can result from tumors located in different parts of the body that produce excessive amounts of the hormone that stimulates cortisol production in the adrenal glands or tumors within the adrenal glands themselves that cause overproduction of cortisol.
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Low Cortisol Level: If the cortisol levels are low, it may indicate Addison's disease or secondary adrenal insufficiency. Addison's disease is usually caused by damage to the adrenal glands, often due to autoimmune diseases or certain infections such as tuberculosis (TB) and HIV/AIDS. Secondary adrenal insufficiency can be caused by autoimmune diseases, problems with the pituitary gland, or traumatic brain injury.
Discontinuing steroid medicines after prolonged use is the primary reason for low cortisol levels. Irregular cortisol levels do not necessarily indicate the need for medical treatment. There are several factors that can affect cortisol levels, such as stress, pregnancy, exercise, serious illness, extreme temperatures, specific thyroid disorders, obesity, and some medications, such as birth control pills.
Conclusion
Cortisol is a hormone that affects various organs and functions of the body, including stress management, inflammation, blood sugar and pressure regulation, and metabolism. The cortisol test detects medical conditions that cause abnormal cortisol levels, such as adrenal gland disorders like Cushing's syndrome, Addison's disease, and secondary adrenal insufficiency. A blood, urine, or saliva sample can be used for this test, but proper preparation and interpretation of results by a qualified healthcare professional are crucial.
