was ist cortisol einfach erklärt — what are common causes?

Cortisol is a vital hormone produced by the adrenal glands. It's often called the 'stress hormone' because it's released during challenges to provide energy (raising blood sugar, reducing inflammation). It follows a natural daily rhythm: high in the morning, low at night. Common causes of high cortisol include chronic stress, lack of sleep, certain tumors (Cushing's syndrome), or use of corticosteroid medications. Persistently high cortisol can lead to weight gain, high blood pressure, immune suppression, and mood swings. Low cortisol (adrenal insufficiency, Addison's disease) causes fatigue, low blood pressure, and skin changes. Important: A single saliva or blood test is not diagnostic – proper evaluation requires dynamic tests (e.g., dexamethasone suppression test) under medical supervision. Supplements or 'cortisol blockers' are not recommended without a clear medical indication and can be harmful. The evidence for cortisol physiology is strong, but many consumer tests overstate the predictive value of single measurements.