Cortisol glossary.
Plain words for the terms behind the claims.

ACTH (adrenocorticotropic hormone).

A hormone made by the pituitary gland that signals the adrenal glands to make cortisol.

Addison’s disease.

A form of primary adrenal insufficiency, in which the adrenal glands do not make enough cortisol. It needs medical care.

Adrenal fatigue.

A term used online for tiredness and other symptoms blamed on “tired” adrenal glands. The Endocrine Society reports no scientific evidence establishing it as a medical condition. It is different from adrenal insufficiency.

Adrenal glands.

Two small glands above the kidneys that make cortisol and other hormones.

Adrenal insufficiency.

A recognized condition in which the body does not make enough cortisol. Evaluation requires medical tests. A severe episode (adrenal crisis) is an emergency.

Circadian rhythm.

The body’s roughly 24-hour internal clock, which influences sleep, alertness and the daily pattern of hormones such as cortisol.

Cortisol.

A steroid hormone made by the adrenal glands. It helps regulate energy use, blood sugar, blood pressure and the response to stress and illness. It is supposed to vary through the day.

Cortisol awakening response.

The rise in cortisol that typically happens in the first hour after waking.

Cushing’s syndrome.

A condition caused by prolonged exposure to high levels of cortisol (or similar medicines). A common cause is long-term use of glucocorticoid medicines. It requires clinical evaluation.

Dexamethasone suppression test.

A test in which a low dose of a steroid medicine is given, then cortisol is measured to see whether it falls as expected.

Glucocorticoid.

A class of steroid hormones and medicines that includes cortisol and drugs such as prednisone. Do not stop a prescribed glucocorticoid without talking to your prescriber.

HPA axis.

The hypothalamic-pituitary-adrenal axis: the chain of signals from the brain (hypothalamus and pituitary) to the adrenal glands that controls cortisol release.

Hypercortisolism.

A medical term for too much cortisol exposure. Cushing’s syndrome is one form.

Moon face.

A rounded, fuller face that can occur with prolonged high cortisol exposure. It usually appears with other signs. It is different from everyday puffiness.

Salivary cortisol.

Cortisol measured in saliva. Late-night salivary cortisol is one test clinicians use when Cushing’s syndrome is suspected.

Stress response.

The body’s short-term reaction to a challenge, which includes the release of cortisol and other hormones.

Viral label.

A term popularized on social media (such as “cortisol belly” or “cortisol face”) that sounds medical but is not a diagnosis.

Visceral fat.

Fat stored deeper in the abdomen, around internal organs. It cannot be judged from appearance alone.

Optional. Educational material, not medical advice. The free tools stay free.