Cushing syndrome happens when the body has too much of the hormone cortisol for a long time. This can result from the body making too much cortisol, or from taking medicines called glucocorticoids, which affect the body the same way as cortisol.
Too much cortisol can cause some of the main symptoms of Cushing syndrome — a fatty hump between the shoulders, a rounded face, and pink or purple stretch marks on the skin. Cushing syndrome also can cause high blood pressure or bone loss. Sometimes, it can cause type 2 diabetes.
Treatments for Cushing syndrome can lower the body's cortisol levels and improve symptoms. The sooner treatment starts, the better the chances for recovery.

Left untreated, Cushing syndrome can result in a rounded face, weight gain around the belly and upper back, thinner arms and legs, easy bruising, and stretch marks.
Symptoms of Cushing syndrome can vary depending on the level of extra cortisol.
Call your health care provider if you have symptoms of Cushing syndrome, especially if you're taking glucocorticoid medicine to treat a health issue such as asthma, arthritis or inflammatory bowel disease.
Cushing syndrome is caused by having too much cortisol in the body. Cortisol is a hormone that is made in the adrenal glands. It helps the body respond to stress and plays many other important roles, including:

The adrenal gland endocrine system includes the adrenal glands and pituitary gland. Signals from the pituitary gland tell the adrenal glands to make cortisol. The pituitary gland knows if the body has the right amount of cortisol.
Cushing syndrome can happen from taking glucocorticoid medicines. These are often used to treat inflammatory diseases such as rheumatoid arthritis, lupus and asthma. Pain or injury in the back or joints and many skin rashes may be treated with glucocorticoids. They also may be used to stop the body from rejecting a new organ after a transplant.
Glucocorticoids may be taken by mouth, given as a shot, rubbed into the skin or breathed into the lungs by an inhaler. Any form of glucocorticoid, if taken in large amounts for a long time, can cause Cushing syndrome.
A hormone made in the pituitary gland controls how much cortisol the body makes. This is called adrenocorticotropic hormone (ACTH). Some tumors make ACTH, which creates more cortisol and can cause Cushing syndrome. Problems with the adrenal glands also can affect cortisol and cause Cushing syndrome.
When Cushing syndrome happens this way, it may be caused by:
Adrenal gland tumors or disease. Problems with the adrenal glands can cause them to make too much cortisol. The most common is a tumor in the outer part of the adrenal gland called an adrenal adenoma. These tumors are not cancer, and only some make too much cortisol.
Cancerous tumors in the outer part of the adrenal glands, known as adrenocortical carcinoma, are rare. But they can make cortisol and cause Cushing syndrome. Sometimes, several lumps that make cortisol can grow in the adrenal glands and cause Cushing syndrome. This is called adrenal nodular hyperplasia.
Without treatment, Cushing syndrome can cause complications, including: