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Causes and pathophysiology of Cushing's syndrome

Lynnette K Nieman, MD
Section Editor
André Lacroix, MD
Deputy Editor
Kathryn A Martin, MD


The diagnosis of Cushing's syndrome involves three steps: suspecting it on the basis of the patient's symptoms and signs, documenting the presence of hypercortisolism, and determining its cause. The last step requires an understanding of the causes and pathophysiology of the different types of Cushing's syndrome; these will be reviewed here. The clinical manifestations, diagnosis, and treatment of Cushing's syndrome are discussed separately. (See "Epidemiology and clinical manifestations of Cushing's syndrome" and "Establishing the diagnosis of Cushing's syndrome" and "Establishing the cause of Cushing's syndrome" and "Overview of the treatment of Cushing's syndrome".)


Hypercortisolism can occur in several disorders other than Cushing's syndrome [1,2]. When such patients present with clinical features consistent with Cushing's syndrome, they may also be referred to as having physiologic hypercortisolism or pseudo-Cushing's syndrome. Clinically, patients with these physiologic forms of hypercortisolism seldom have the cutaneous (ie, easy bruising, thinning, and friability) or muscle (ie, proximal muscle atrophy and weakness) signs of Cushing's syndrome [3]. However, these conditions/disorders should be excluded when evaluating patients for Cushing's syndrome. (See "Establishing the diagnosis of Cushing's syndrome", section on 'Exclude physiologic hypercortisolism'.)

Examples of conditions associated with physiologic hypercortisolism that may have some clinical features of Cushing's syndrome include:


Patients with severe obesity, especially those with visceral obesity or polycystic ovary syndrome (PCOS)


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Literature review current through: Jan 2017. | This topic last updated: Wed Feb 15 00:00:00 GMT+00:00 2017.
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