How do you diagnose Cushing’s disease? How is Cushing’s diagnosed?

Cushing’s disease is a condition that occurs when the body produces too much of the hormone cortisol. Diagnosing Cushing’s disease can be a complex process and often involves several steps.

The first step in diagnosing Cushing’s disease is usually a physical examination. During this examination, a doctor will look for signs of Cushing’s disease, such as a round face, a hump on the back of the neck, and thin, bruised skin with stretch marks.

If a person hasn’t been using a glucocorticoid medicine, which is the most common way to get Cushing’s syndrome, the doctor may order several tests to help diagnose Cushing’s disease. These tests can include:

Urine and blood tests: These tests measure hormone levels and show if the body is making too much cortisol. For the urine test, a person may be asked to collect their urine over a 24-hour period. Cortisol, ACTH, and other hormones are measured in urine and blood samples.

Saliva test: Cortisol levels typically rise and fall during the day. In people without Cushing’s syndrome, cortisol drops in the evening. By looking at cortisol levels from a small sample of saliva collected at night, the health care team can see if cortisol levels are too high.

Imaging tests: CT or MRI scans can take pictures of the pituitary and adrenal glands to see if anything shows up, such as tumors.

Inferior petrosal sinus sampling: This test can help decide if Cushing’s syndrome is caused by an ACTH-producing pituitary adenoma, or ACTH-producing tumor in another organ. During the test, blood samples are taken from the veins that drain the pituitary gland, called the inferior petrosal sinuses. Levels of ACTH are then compared between the two sample areas. If the ACTH level is higher in the sinus sample, the problem is coming from the pituitary. If the ACTH levels are similar between the sinuses and forearm, the problem is outside of the pituitary gland.

These tests help the doctor diagnose Cushing’s syndrome and may also help rule out other health conditions, such as polycystic ovary syndrome, depression, eating disorders, and alcoholism, which can have symptoms similar to Cushing’s syndrome.

Once a diagnosis of Cushing’s disease has been made, the doctor will work with the patient to develop a treatment plan. This plan will depend on the cause of the disease and may include medication, surgery, radiation therapy, or a combination of these treatments. The goal of treatment is to reduce the high levels of cortisol in the body and alleviate the symptoms of Cushing’s disease.