Cushing\'s Disease Anatomy and Physiology

Cushing's disease, as well as Cushing's syndrome, is caused by the overproduction of something called cortisol. Cortisol is "a normal hormone produced in the outer portion, or cortex, of the adrenal glands" (Margulies). Whether your body naturally overproduces this hormone, or your body receives too much cortisol in steroid medications used as treatment for other diseases, it can lead to development of Cushing's disease.

In normal function, cortisol helps the body respond to changes and to stressors. Its normal functions include the mobilization of nutrients, modifying the body's response to inflammation, getting the liver to raise blood sugar levels, and regulating the amount of water in the body (Margulies). Adrenocorticotrophic hormone (ACTH for short) is made by the pituitary gland, and regulates cortisol production. Overproduction of cortisol, or taking in excess amounts via medications causes significant changes in "all of the tissues and organs of the body" (Margulies). The culmination of these changes is what is typically labeled "Cushing's disease" or "Cushing's syndrome"; dependent upon the way the condition has developed. According to the American Academy of Family Physicians, "Cushing's syndrome" is used to describe the condition when it is the direct result of the body's long-term exposure to excessive amounts of cortisol through medications. "Cushing's disease" is used for patients who have the condition because of the excessive production of cortisol by a pituitary tumor. (Kirk, 1119)

According to the American Family Physician magazine, some of the common symptoms of Cushing's disease as well as Cushing's syndrome include (Kirk, 1133):

Weight gain, because of fat deposit formation around the stomach and upper back area.

Thin skin, which is easily bruised - minor scrapes take much longer to heal, as well.

Fatigue, accompanied by weak muscles in the upper body.

Women may begin to have irregular periods, along with significantly thicker and more visible body hair.

High blood pressure, osteoporosis, and diabetes can be indicators.

Family doctors can usually diagnose patients with either Cushing's disease or syndrome. It begins with a physical exam, looking for the common physical characteristics of the illness. If the cause is medicines that are being used to treat other illnesses (asthma, systemic lupus, severe allergies, inflammatory bowel disease, rheumatoid arthritis and others {Margulies}), no further testing is usually required (Kirk, 1134). Urine and blood tests are used to diagnose the disease in those who are not taking any steroid medications. Some patients may need a CT scan or an MRI, which will show any tumors present (Kirk, 1134).

Treatment of Cushing's disease usually involves the removal of the tumor from the pituitary gland, which alone is usually successful. This surgery is usually performed by a neurosurgeon using a procedure called "transsphenoidal resection" which means "behind the nose" (Margulies). Sometimes, the entire pituitary gland is removed, which results in the giving of replacement hormones for those missing - "cortisol, thyroid and gonadal (sex) hormones" (Margulies). Radiation treatments may occur after surgery (or if surgery cannot be performed), as well as the prescription of medicines that are "cortisone-like" for several months following the tumor removal (Kirk, 1134).

Cushing's syndrome is not so easily remedied, if the illness for which the steroids are being used is severe enough to cause than the Cushing's syndrome itself. If the medicines are stopped, the body will return to its normal condition. In these extreme cases, the syndrome is managed through diet and medications (for high blood sugar), replacement of potassium, treatment of the high blood pressure, increased calcium intake, as well as adjusting the steroid intake during severe illnesses, any surgical procedures, or injuries (Margulies).

The life of someone with either Cushing's disease or Cushing's syndrome depend on the severity of the cortisol excess, the duration, the overall health of the person, and the type (as well as curability) of the Cushing's syndrome. Resolution of the symptoms after being cured can take 2-18 months, during which time some patients are frustrated with the slow progression of their recovery (Margulies). When Cushing's syndrome cannot be cured, a lifetime of dealing with persistent fatigue, weakness in the muscles, abdominal and facial weight gain, depression, and all the aforementioned symptoms (Margulies).