Cortisol Blood Test - Know All About It

Introduction:

Cortisol, also called the stress hormone, is a steroid hormone that is released by the adrenal glands. The adrenal glands are situated on the top of the kidneys. The cortisol hormone is essential for various body functions. A sample of blood, saliva, urine, or a combination is used for cortisol testing. A cortisol test is also known as free cortisol, urinary cortisol, blood cortisol, plasma cortisol, or salivary cortisol. The cortisol blood test aids in diagnosing disorders that affect the adrenal glands.

What Is the Role of Cortisol?

Cortisol is referred to as the stress hormone. Whenever an individual perceives something to be a threat, a chemical called the adrenocorticotropic hormone (ACTH) is released in the brain. This stimulates the adrenal glands to release the hormones cortisol and adrenaline. Cortisol is the major hormone that is responsible for the fight, flight, or freeze response. This is the body’s natural way of protecting oneself from a perceived threat or danger.

During the fight, flight, or freeze response, unnecessary or unwanted functions detrimental to that response are suppressed by the cortisol hormone. During the fight, flight, or freeze response, one experiences the following:

• A rapid heart rate.

• Stomach upset.

• Dry mouth.

• Diarrhea.

• Panic.

The release of cortisol also suppresses the digestive system, growth processes, and reproductive system, and alters the response of the immune system.

What Does the Cortisol Test Help Diagnose?

A cortisol test detects too much or too little presence of the hormone cortisol in the body. These results can help diagnose the following conditions:

• Cushing’s Syndrome: Cushing’s syndrome is also known as hypercortisolism and manifests when the body produces excessive cortisol.

• Addison’s Disease: Addison’s disease is also known as primary adrenal insufficiency or hypocortisolism and manifests when the body produces too little cortisol.

• The cortisol test helps detect the presence of a tumor that interferes with the production of cortisol. Various tumors may result in elevated cortisol levels.

The normal value of cortisol in a blood sample taken at 8 a.m. ranges between 5 to 25 mcg/dL. However, there can be a wide variation in the results, depending on the time at which the test was done and other factors that influence cortisol levels.

What Are the Symptoms of High and Low Cortisol Levels?

The symptoms of high cortisol levels are as follows:

• Diabetes.

• Changes in sex drive.

• Red, round face.

• Balding or excessive hair growth.

• High blood pressure.

• Poor wound healing.

• Appearance of purple stretch mark over the abdomen.

• Weight gain and mood swings.

• Elevated risk of blood clots, and increased risk of weak bones and fracture risk.

• Stunted growth in children.

• Weak muscles, thin arms and legs, and easy bruising on the arms and legs.

The symptoms of low cortisol levels are as follows:

• Irritability, abdominal pain, and dehydration.

• Abnormal menstrual cycle.

• Loss of appetite, cravings for salty food, and unexplained weight loss.

• Hypotension (low blood pressure) or hypoglycemia (low blood glucose).

• Diarrhea or nausea and vomiting.

• Muscle weakness, particularly while combing the hair and climbing the stairs.

• Darkening of gums, lips, and palms, and patches of dark skin.

How Is the Cortisol Test Performed?

Cortisol levels are measured by obtaining a blood sample. The procedure for collecting a blood sample is as follows:

• The blood flow in the arm is temporarily stopped by wrapping an elastic band around the upper arm. By doing this, the veins in the arm appear more visible, which makes needle insertion easier.

• The site of insertion of the needle on the skin is cleaned using alcohol.

• The needle is then gently inserted into the vein. This might create a transient stinging or pinching sensation. The blood is then collected in a tube that is attached to the needle.

• The elastic band is then unwrapped from the arm after sufficient blood sample has been obtained.

• As the needle is withdrawn from the skin, a small piece of cotton is placed on the site where the needle was inserted.

• Gentle pressure is applied to the area using cotton. A bandage may be used to keep the cotton in place.

In the case of a saliva test, a healthcare professional may insert a swab in the mouth and wait for a few minutes till the swab gets saturated with sufficient samples. If one decides to perform the test at home, then the healthcare professional will instruct the individual about when to perform the test and how to return the obtained sample.

In a urine test, a container is given to the individual to collect the urine over a period of 24 hours. One may be asked to store the urine in a cold place. Cortisol testing may need to be repeated twice a day or multiple times over a few days since the levels of cortisol vary.

A few instructions may be given by the physician prior to a cortisol test. One might be asked not to brush, drink, or eat before a salivary test. Similarly, one might be asked to rest before the test so that stress does not affect the test results.

What Can Interfere With the Cortisol Level Values?

Cortisol levels keep changing throughout the day but are usually at their peak in the morning. Hence, the physician will recommend taking the test in the morning. Certain drugs can affect the levels of cortisol and hence the physician may advise the individual to not take these drugs prior to the test. At times, the levels of cortisol may be increased by:

• Pregnancy.

• Drugs containing estrogen.

• Synthetic glucocorticoids like Prednisone.

On the contrary, the levels of cortisol may be decreased by phenytoin and drugs containing androgens. Stress and illness can also influence the cortisol levels.

Is the Cortisol Test Associated With Any Risks?

A few risks may be associated with the cortisol test. Since the test is performed by drawing blood from the vein, there are chances of mild bruising at the site of insertion of the needle. Very rarely, the following risks may occur after drawing blood from the vein:

• Fainting or lightheadedness.

• Excessive bleeding.

• Hematoma (accumulation of blood beneath the skin).

• Infection.

Urine and saliva tests are not known to have any risks. The results of the cortisol test may take about one to five days to arrive depending on the physician and the laboratory.

What Do the Results of the Cortisol Test Indicate?

High cortisol levels may indicate the following:

• A tumor in the adrenal gland that is producing excessive cortisol.

• Tumors present elsewhere in the body, like small cell lung cancer.

• Effects of large quantities of certain medications.

• A tumor in the pituitary gland that is producing ACTH, which triggers cortisol production.

Low cortisol levels may indicate the following:

• Underactive pituitary gland.

• Damaged or underactive adrenal glands.

• A tumor in the pituitary gland that retards ACTH production.

Conclusion:

The levels of cortisol in the body are measured by a cortisol test. This aids in the diagnosis of an adrenal disorder like Addison’s disease or Cushing’s Syndrome. This test also helps assess the functioning of the pituitary and adrenal glands. Cortisol plays an important role in various systems in the body like the immune system, skeletal system, nervous system, circulatory system, stress responses, and in the breakdown of fats, proteins, and carbohydrates. A physician might suggest taking other tests if they believe that the cortisol levels in the blood are too low or too high.