Cushing’s syndrome results from prolonged exposure to high levels of the hormone cortisol in the body. Cortisol, often called the stress hormone, helps regulate blood pressure, blood sugar, and the immune system. However, too much cortisol can lead to various physical changes and health complications. Understanding the nature of this condition requires knowing what causes it and how it differs from illnesses that pass between people.
Why Cushing’s is Not Transmissible
Cushing’s is an endocrine disorder, meaning it involves a malfunction of the body’s hormone-producing glands, not an infectious agent. Contagious diseases require a specific pathogen, such as a virus, bacteria, fungus, or parasite, to be transmitted through contact or droplets. The excess cortisol defining Cushing’s syndrome cannot be transferred to another person through any of these routes. Since the physical and chemical processes occur entirely within the affected individual, the condition is not infectious and cannot be spread. This places Cushing’s firmly in the category of non-communicable diseases, similar to diabetes or thyroid disorders.
Internal Origins of the Disorder
The causes of Cushing’s syndrome are broadly divided into two categories: exogenous (external to the body) and endogenous (originating from within).
Exogenous Causes
The most frequent cause stems from the long-term, high-dose therapeutic use of corticosteroid medications like prednisone. These drugs are prescribed to manage inflammatory conditions such as asthma, lupus, and rheumatoid arthritis. Their chemical similarity to cortisol can artificially elevate hormone levels in the body.
Endogenous Causes
Endogenous causes involve an overproduction of cortisol by the body’s own system, typically due to tumors. Cushing’s Disease is a specific type of endogenous Cushing’s syndrome where a benign tumor, called an adenoma, forms on the pituitary gland at the base of the brain. This tumor secretes excess adrenocorticotropic hormone (ACTH), which signals the adrenal glands to produce too much cortisol. This pituitary cause accounts for about 70 to 80 percent of all endogenous cases.
Other internal origins include tumors directly on the adrenal glands, which are the small organs located above the kidneys that produce cortisol. These adrenal tumors can be benign or, less commonly, cancerous. A rare third cause is ectopic ACTH production, where tumors outside the pituitary gland (such as the lungs or pancreas) begin secreting ACTH, stimulating cortisol overproduction.
Symptoms and Who is at Risk
Chronic exposure to high cortisol levels leads to distinct physical manifestations affecting metabolism and body composition. Characteristic signs include weight gain concentrated in the abdomen, face (“moon face”), and between the shoulders (“buffalo hump”). Patients also experience thinning, fragile skin that bruises easily, and purple or pink stretch marks (striae) on the abdomen, thighs, and breasts. Muscle weakness is common, alongside psychological changes like depression, anxiety, and irritability. Individuals with poorly controlled type 2 diabetes and high blood pressure may have an increased likelihood of having Cushing’s syndrome, though rare genetic syndromes can predispose individuals to develop the endocrine tumors that lead to the condition.