Cortisol is a stress hormone produced by the adrenal glands. Producing too much or too little of this hormone can cause disorders that disrupt a patient’s health, such as Cushing’s Syndrome or Addison’s Disease. Measuring cortisol levels is an important part of diagnosing these conditions and monitoring their treatment. Testing salivary cortisol levels, rather than blood or urine cortisol levels, is increasing in popularity among medical professionals because it potentially causes less stress and can be done in the home.
Hormone production is very complex. Cortisol is found throughout the body, but is manufactured by the adrenal glands. It is one of the stress hormones, and is produced at higher levels in individuals who are prone to stress. Aside from contributing factors such as work and emotions, it is also produced at greater levels by people who work early morning shifts.
In most people, cortisol levels decrease while sleeping, and increase after awakening. Light affects this pattern of hormone production. Cortisol levels in the saliva, also known as salivary cortisol levels, are higher when individuals awaken in the light as opposed to the darkness. Also, morning people have higher levels in the morning than do night owls.
Alterations in the levels of cortisol can have profound effects on a person’s physiology. Traditionally, this hormone has been monitored by tests of the blood and urine. Levels in the saliva have been found to correlate well with the levels in the blood. The test is being used more frequently to determine the levels of this hormone.
One advantage of this type of measurement is that it can be done in the home. This eliminates a layer of stress from being in a doctor’s office or lab that could potentially affect the test results. It also makes it easier to perform multiple tests over the course of a day.
Salivary cortisol levels can be too high or too low. The presence of an excessive amount of hormone in the bodily fluids is frequently due to a disorder known as Cushing’s Syndrome. This disorder is due to an overproduction of cortisol by the adrenal glands. In addition to disrupting the overall amount of hormone produced, this syndrome also changes the pattern of hormone production. The classic morning/night differences in salivary cortisol are no longer observed.
In contrast, some other patients produce inadequate levels of this hormone. This can be due to damage to the adrenal glands. In this case, both morning and night salivary cortisol tests reveal low levels of the hormone. This condition is known as Addison’s Disease.