What is the difference between Cushing's syndrome and Cushing's disease?

Cushing's syndrome is the broader term for any condition causing excess cortisol, regardless of the source. Cushing's disease specifically refers to Cushing's syndrome caused by a pituitary adenoma that produces excess ACTH, which in turn stimulates the adrenal glands to produce too much cortisol. Cushing's disease is the most common endogenous cause of Cushing's syndrome, accounting for about 70% of non-medication-related cases.

Can Cushing's syndrome be cured?

If Cushing's syndrome is caused by a tumor (pituitary or adrenal), surgical removal can be curative in many cases, with success rates of 65-90% for pituitary surgery. If caused by exogenous corticosteroids, gradual tapering under medical supervision can resolve the syndrome. However, recovery from the effects of prolonged excess cortisol—including bone loss and metabolic changes—can take months to years.

Is Cushing's syndrome life-threatening?

Yes, untreated Cushing's syndrome can be life-threatening due to complications such as uncontrolled diabetes, severe infections from immune suppression, cardiovascular disease, blood clots, and osteoporotic fractures. The mortality rate is significantly elevated in untreated patients compared to the general population. Early diagnosis and appropriate treatment dramatically improve outcomes and life expectancy.

EndocrineICD-10: E24.9Endogenous Cushing's syndrome affects approximately 2-3 per million people per year; iatrogenic cases are much more common

Cushing's Syndrome

Cushing's syndrome is a hormonal disorder caused by prolonged exposure to high levels of the hormone cortisol, either from the body's own overproduction (endogenous) or from long-term use of corticosteroid medications (exogenous). When the syndrome is caused by a pituitary adenoma stimulating excess cortisol production, it is specifically called Cushing's disease. Cushing's syndrome affects multiple body systems and can lead to serious complications including diabetes, osteoporosis, hypertension, and cardiovascular disease if untreated.

At a Glance

Common symptoms: Weight gain, particularly in the face (moon face), upper back (buffalo hump), and abdomen, Pink or purple stretch marks (striae) on the abdomen, thighs, breasts, and arms, Thinning, fragile skin that bruises easily
Main treatments: Gradual tapering and discontinuation of exogenous corticosteroids (if applicable), Transsphenoidal surgery to remove pituitary adenomas (Cushing's disease), Adrenalectomy (surgical removal of adrenal tumors)
Category: Endocrine · Endogenous Cushing's syndrome affects approximately 2-3 per million people per year; iatrogenic cases are much more common
See a doctor if: You develop unexplained weight gain with central obesity, skin changes, and muscle weakness

Symptoms

Weight gain, particularly in the face (moon face), upper back (buffalo hump), and abdomen

Pink or purple stretch marks (striae) on the abdomen, thighs, breasts, and arms

Thinning, fragile skin that bruises easily

Slow wound healing

Muscle weakness, especially in the upper arms and thighs

High blood pressure

High blood sugar or new-onset diabetes

Bone loss (osteoporosis) and increased fracture risk

Mood changes including depression, anxiety, and irritability

Causes

Long-term use of oral corticosteroid medications (most common cause)
Pituitary adenoma producing excess ACTH (Cushing's disease)
Adrenal tumors (adenoma or carcinoma) producing excess cortisol
Ectopic ACTH syndrome from tumors in the lungs, pancreas, or other organs

Risk Factors

Chronic use of corticosteroid medications (prednisone, dexamethasone) for conditions like asthma, arthritis, or lupus
Female sex (endogenous Cushing's syndrome is 3-5 times more common in women)
Age 20-50 years at diagnosis
Type 2 diabetes that is difficult to control
Obesity with high blood pressure and unusual fat distribution

Diagnosis

24-hour urinary free cortisol test
Late-night salivary cortisol test
Low-dose dexamethasone suppression test (1 mg overnight test)
Plasma ACTH levels to differentiate ACTH-dependent from ACTH-independent causes
MRI of the pituitary gland or CT of the adrenal glands to locate tumors
Inferior petrosal sinus sampling (IPSS) to confirm pituitary source of ACTH

Treatment

Gradual tapering and discontinuation of exogenous corticosteroids (if applicable)
Transsphenoidal surgery to remove pituitary adenomas (Cushing's disease)
Adrenalectomy (surgical removal of adrenal tumors)
Medications to control cortisol production (ketoconazole, metyrapone, osilodrostat, mifepristone)
Radiation therapy for residual or recurrent pituitary tumors
Treatment of associated conditions (diabetes, hypertension, osteoporosis)

Prevention

Use the lowest effective dose of corticosteroid medications for the shortest duration necessary
Explore steroid-sparing therapies when treating chronic inflammatory conditions
Regular monitoring during long-term corticosteroid therapy
No prevention for endogenous causes, but early recognition and diagnosis are key

When to See a Doctor

You develop unexplained weight gain with central obesity, skin changes, and muscle weakness
You are on long-term corticosteroids and develop cushingoid features
You have new-onset diabetes with high blood pressure and unusual body changes

Frequently Asked Questions

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