Cushing's Syndrome

Too much cortisol has several possible addresses
Clinical review September 2026

Name the excess before naming the source
Cushing syndrome means the body is exposed to too much cortisol. Cortisol is essential for responding to stress, but persistent excess affects muscle, skin, blood pressure, glucose, mood, bone and infection risk. Features may include easy bruising, purple stretch marks, proximal muscle weakness, new diabetes, changes in mood or a rounded face, yet no single feature makes the diagnosis.

Cushing disease is one route
Cushing disease is the pituitary form of Cushing syndrome: a pituitary adenoma makes ACTH, which tells the adrenal glands to make cortisol. Other causes include adrenal cortisol production, ACTH from elsewhere, and prescribed steroid medicines. This distinction is fundamental because treatment follows the source, not the adjective “Cushing”.
 
Screening uses carefully selected tests such as late-night salivary cortisol, 24-hour urine free cortisol or an overnight dexamethasone suppression test. Results can be affected by shift work, alcohol, depression, medicines and illness; more than one test is often needed.
 
A specialist path is worth the patience
After confirming cortisol excess, clinicians work stepwise to identify the source. If pituitary Cushing disease is confirmed, transsphenoidal surgery is usually first treatment. Medicines, radiotherapy, adrenal surgery and management of complications can all have a role when control is not immediate. Never stop prescribed steroid treatment abruptly without medical advice; low cortisol can be dangerous.
 
Important safety note
This page is general education, not personal medical advice. Seek urgent help for sudden severe headache, new visual loss or double vision, collapse, confusion, seizure, or acute severe illness. Follow individual instructions from your endocrine team for medicines and investigations.
 
Further reading

• Pituitary Society Cushing disease guideline