What is Cushing's syndrome?
Cushing's syndrome (hypercortisolism) is a cluster of signs and symptoms caused by having too much cortisol for a long time. It is named after the American neurosurgeon Harvey Cushing, who described patients with pituitary tumors in 1932. Cortisol is essential for regulating blood sugar, blood pressure and immunity, but in excess it affects metabolism, bones, skin and mood.
Causes: Cushing's syndrome vs. Cushing's disease
- Exogenous (medication-induced): long-term oral, inhaled at high doses, or injected steroids for conditions like rheumatoid arthritis or asthma. This is the most common cause.
- Cushing's disease: a pituitary adenoma makes too much ACTH, which drives the adrenal glands. It is the most common internal cause.
- Adrenal tumors that make cortisol on their own
- Ectopic ACTH: rare tumors elsewhere, such as in the lung, that produce ACTH
In other words, Cushing's disease is one specific cause of Cushing's syndrome.
Signs and symptoms
Classic features include a round, flushed "moon face," weight gain in the belly and upper back (a "buffalo hump") with thin arms and legs, wide purple stretch marks, and thin skin that bruises easily. People may also develop high blood pressure, diabetes, osteoporosis, muscle weakness, irregular periods, depression or insomnia. Because these overlap with metabolic syndrome, careful testing matters.
Testing and treatment
The Endocrine Society guideline (Nieman et al., 2008) recommends first ruling out steroid use, then screening with at least one of: 24-hour urine free cortisol, late-night salivary cortisol, or the low-dose dexamethasone suppression test. If results are abnormal, ACTH levels and MRI or CT scans help find the source. Treatment depends on the cause: steroid-induced cases are managed by tapering the drug under medical supervision, and tumors are usually removed surgically (Lacroix et al., 2015). Never stop steroids abruptly on your own, because that can trigger adrenal insufficiency.
This article is general health information and is not a substitute for diagnosis or treatment. If symptoms persist, see a doctor.
FAQ
- Can stress cause Cushing's syndrome?
- No. Everyday stress raises cortisol briefly, but Cushing's syndrome means abnormally high levels for months. The normal stress response is covered in general adaptation syndrome.
- Should I worry if my face gets rounder?
- It is hard to tell apart from ordinary weight gain. Purple stretch marks, easy bruising and muscle weakness together are reasons to see an endocrinologist.
Sources reviewed: 2026-10-25
References
- Cushing, H. (1932). The basophil adenomas of the pituitary body and their clinical manifestations (pituitary basophilism). Bulletin of the Johns Hopkins Hospital, 50, 137–195.
- Nieman, L. K., Biller, B. M. K., Findling, J. W., Newell-Price, J., Savage, M. O., Stewart, P. M., & Montori, V. M. (2008). The diagnosis of Cushing's syndrome: An Endocrine Society clinical practice guideline. Journal of Clinical Endocrinology & Metabolism, 93(5), 1526–1540.
- Lacroix, A., Feelders, R. A., Stratakis, C. A., & Nieman, L. K. (2015). Cushing's syndrome. The Lancet, 386(9996), 913–927.