Definition
Cushing’s disease is characterized by an increased level of cortisol in the body due to a mostly benign tumor of the pituitary gland. The tumor cells produce a messenger substance in large quantities, the so-called adrenocorticotropic hormone, or ACTH for short. This acts on the cells in the adrenal cortex and causes them to produce cortisol. Since the tumor cells produce ACTH in enormously increased quantities, the cells of the adrenal cortex are also stimulated to overproduce it. This ultimately leads to a strongly increased cortisol occurrence, which is called hypercortisolism in medical terminology.
The causes
The cause of Cushing’s disease is usually a tumor in the pituitary gland. The tumor is caused by cell proliferation or uninhibited cell proliferation of misdirected cells. The tumor cells are disturbed in their function. In contrast to the healthy cells of the pituitary gland, they produce abnormally high amounts of ACTH, a messenger substance that affects other organs, especially the adrenal gland. This reacts to the oversupply with an increased cortisol production, which can be accompanied in large quantities with a strong deviation and change of various body functions.
The diagnosis
The diagnosis of Cushing’s disease is usually made by a blood test. This involves looking for cortisol in the blood. In addition, the ACTH value can be determined, which is characteristically elevated in Cushing’s disease.
Certain tests can be performed to differentiate between Cushing’s disease and other diseases that are also associated with elevated cortisol. The so-called dexamethasone test has proved particularly effective in this case. An increased amount of cortisol can also be detected in the 24-hour collective urine. Furthermore, an imaging of the head is performed. As a rule, an MRI of the head is made, on which the tumor in the pituitary gland can then be imaged.
The symptoms
Overproduction of cortisol, which occurs in Cushing’s disease, can cause a variety of symptoms. In the following, the most common changes are listed, but it should be noted that not every symptom is necessarily present to indicate Cushing’s disease. Especially typical is a redistribution of body fat, which manifests itself in a so-called trunk obesity, a full moon face and a bull neck.
The cortisol also affects the bones, which lose density and osteoporosis develops. The muscles also suffer from the increased influence of cortisol and are broken down faster, especially in the extremities. The body reacts more sensitively to sugar or glucose, and the blood sugar level rises more strongly after the intake of sugar than is usual in healthy people.
The skin is also affected. Typical symptoms are thinning of the skin, formation of stretch marks, wound healing disorders and skin bleeding. The psyche can also suffer from the increased cortisol level.
Those affected may experience mood changes and even depressive episodes. In the context of Cushing’s disease, there is not only an increased cortisol level but also a change in the ACTH level in the blood. This leads to an increased production of sex hormones, especially the male hormones, the so-called androgens.
This is particularly noticeable in women who then suffer from menstrual disorders or increased hair growth, especially on the face. ACTH or cortisol also has an influence on blood pressure. Through an interaction with other hormones it comes to an increase in blood pressure, which then becomes noticeable as high blood pressure.
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