Cushing syndrome


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Cushing syndrome

Endocrine system

Adrenal gland disorders

Congenital adrenal hyperplasia

Primary adrenal insufficiency

Waterhouse-Friderichsen syndrome


Adrenal cortical carcinoma

Cushing syndrome

Conn syndrome

Thyroid gland disorders

Thyroglossal duct cyst


Graves disease

Thyroid eye disease (NORD)

Toxic multinodular goiter

Thyroid storm


Euthyroid sick syndrome

Hashimoto thyroiditis

Subacute granulomatous thyroiditis

Riedel thyroiditis

Postpartum thyroiditis

Thyroid cancer

Parathyroid gland disorders





Pancreatic disorders

Diabetes mellitus

Diabetic retinopathy

Diabetic nephropathy

Pituitary gland disorders


Pituitary adenoma






Growth hormone deficiency

Pituitary apoplexy

Sheehan syndrome


Constitutional growth delay

Diabetes insipidus

Syndrome of inappropriate antidiuretic hormone secretion (SIADH)

Gonadal dysfunction

Precocious puberty

Delayed puberty

Premature ovarian failure

Polycystic ovary syndrome

Androgen insensitivity syndrome

Kallmann syndrome

5-alpha-reductase deficiency

Polyglandular syndromes

Autoimmune polyglandular syndrome type 1 (NORD)

Endocrine tumors

Multiple endocrine neoplasia

Pancreatic neuroendocrine neoplasms

Zollinger-Ellison syndrome

Carcinoid syndrome



Opsoclonus myoclonus syndrome (NORD)

Endocrine system pathology review

Adrenal insufficiency: Pathology review

Adrenal masses: Pathology review

Hyperthyroidism: Pathology review

Hypothyroidism: Pathology review

Thyroid nodules and thyroid cancer: Pathology review

Parathyroid disorders and calcium imbalance: Pathology review

Diabetes mellitus: Pathology review

Cushing syndrome and Cushing disease: Pathology review

Pituitary tumors: Pathology review

Hypopituitarism: Pathology review

Diabetes insipidus and SIADH: Pathology review

Multiple endocrine neoplasia: Pathology review

Neuroendocrine tumors of the gastrointestinal system: Pathology review


Cushing syndrome


0 / 17 complete

USMLE® Step 1 questions

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High Yield Notes

5 pages


Cushing syndrome

of complete


USMLE® Step 1 style questions USMLE

of complete

A 52-year-old man comes to his physician due to progressive weight gain over the past 6 months. The patient has moderate, persistent bronchial asthma, which is well-controlled with as-needed inhaled corticosteroids and albuterol. His temperature is 37.0°C (98.6°F), pulse is 82/min, and blood pressure is 161/96 mmHg. There are scattered ecchymoses on the extremities and mild proximal muscle weakness is present. Laboratory testing and imaging is performed to confirm the diagnosis. Abdominal CT reveals an adrenal tumor on the right side, with mild atrophy of the left adrenal gland. This patient most likely has which of the following laboratory patterns of hypothalamic-pituitary-adrenal axis activity?  

External References

First Aid








Adrenal adenomas

Cushing syndrome p. 354

Adrenal carcinomas

Cushing syndrome p. 354

Adrenal hyperplasia

Cushing syndrome p. 354

Adrenocorticotropic hormone (ACTH)

in Cushing syndrome p. 221, 354


Cushing syndrome p. 354


Cushing syndrome p. 354

Corticotropin-releasing hormone (CRH) p. 335

Cushing syndrome and p. 354

Cortisol p. 337

in Cushing syndrome p. 354

Cushing disease p. 354

Cushing syndrome p. 354

acanthosis nigricans and p. 495

anovulation with p. 669

corticosteroids p. 118

hirsutism p. 354

paraneoplastic syndrome p. 221

small cell lung cancer p. 709


Cushing syndrome diagnosis p. 354


Cushing syndrome diagnosis p. 354


Cushing syndrome p. 354

Hypertension p. 306

Cushing syndrome p. 354

Insulin resistance

Cushing syndrome p. 354


Cushing syndrome p. 354

Osteoporosis p. 472

Cushing syndrome p. 354


Cushing syndrome and p. 354

Weight gain

Cushing syndrome p. 354

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Content Reviewers

Rishi Desai, MD, MPH


Antonia Syrnioti, MD

Brittany Norton, MFA

Tanner Marshall, MS

Cushing syndrome, named after the famous neurosurgeon, Harvey Cushing who first described it, is an endocrine disorder with elevated cortisol levels in the blood. In some cases, Cushing syndrome results from a pituitary adenoma making excess ACTH, and in those situations it’s called Cushing disease

Normally, the hypothalamus, which is located at the base of the brain, secretes corticotropin-releasing hormone, known as CRH, which stimulates the pituitary gland to secrete adrenocorticotropic hormone, known as ACTH. ACTH, then, travels to the pair of adrenal glands, on top of each kidney, where it specifically targets cells in the adrenal cortex.

The adrenal cortex is the outer part of the adrenal gland and is subdivided into three layers- the zona glomerulosa, the zona fasciculata, and the zona reticularis. Zona fasciculata is the middle zone and also the widest zone and it takes up the majority of the volume of the whole adrenal gland.

The ACTH specifically stimulates cells in this zone to secrete cortisol, which belongs to a class of steroids, or lipid-soluble hormones, called glucocorticoids. Glucocorticoids are not soluble in water, so most cortisol in the blood is bound to a special carrier protein, called cortisol-binding globulin, and only about 5% is unbound or free. In fact, only this small fraction of free cortisol is biologically active, and its levels are carefully controlled. Excess free cortisol is filtered in kidneys and dumped into the urine. 

Free cortisol in the blood is involved in a number of things and it’s part of the circadian rhythm. Cortisol levels peak in the morning, when the body knows we need to “get up and go” and then drop in the evening, when we’re preparing for sleep. In times of stress, the body needs to have plenty of energy substrates around, so cortisol increases gluconeogenesis, which is the synthesis of new glucose molecules, proteolysis, which is the breakdown of protein and lipolysis, which is the breakdown of fat.


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  2. "Harrison's Principles of Internal Medicine, Twentieth Edition (Vol.1 & Vol.2)" McGraw-Hill Education / Medical (2018)
  3. "Pathophysiology of Disease: An Introduction to Clinical Medicine 8E" McGraw-Hill Education / Medical (2018)
  4. "A Physiologic Approach to Diagnosis of the Cushing Syndrome" Annals of Internal Medicine (2003)
  5. "Cushing's syndrome: update on signs, symptoms and biochemical screening" European Journal of Endocrinology (2015)
  6. "Cushing's disease" Best Practice & Research Clinical Endocrinology & Metabolism (2009)

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