Description
Cortisol is the most important steroid hormone.
About 80% of the 17-Hydrocorticoidsteroids in circulation are cortisol, while 90% are protein-bound and the remaining is freely available, which is biologically active and can be measured in saliva, serum and urine.
In saliva, there is a diurnal fluctuation of the cortisol concentration in adult humans, reaching a peak between 30-60 minutes after waking. Levels begin to fall lower levels throughout the afternoon, reaching their lowest levels prior to bedtime. This response can be either enhanced or diminished during periods of chronic stress, exhaustion, depression as well as other clinical disorders.
Salivary cortisol measurement is relevant in diseases with abnormal glucocorticoid production. Hypercortisolism describes the overproduction of cortisol, known as Cushing Syndrome and Hypocortisolism describes the underproduction of cortisol, known as Addison’s Disease.