ACTH test is requested when a patient has signs or symptoms of certain diseases, including Cushing syndrome or Addison disease and has abnormal or inappropriate blood cortisol levels.Cushing syndrome is a group of disorders caused by too much cortisol. It can cause symptoms such as obesity, a rounded face, fragile and thin skin, purple lines on the tummy, muscle weakness, acne, and increased body hair. It is often seen with other physical and laboratory signs, including high blood pressure, low potassium, high bicarbonate, and high glucose (or even diabetes). When Cushing syndrome is due to a tumour in the pituitary gland that makes ACTH this is referred to as Cushing disease. Other causes of Cushing syndrome include adrenal tumours that make cortisol, tumours in other parts of the body (usually the lungs) that make ACTH (which then stimulates the adrenal glands to make cortisol), and taking high dose steroids prescribed by your doctor.Addison disease is due to a lack of cortisol, and is found to have symptoms such as muscle weakness, tiredness, weight loss, increased skin pigmentation (even in areas not exposed to the sun) and loss of appetite, often accompanied by laboratory and physical signs such as low blood pressure, low blood glucose, low sodium, high potassium, and high calcium. Congenital Adrenal Hyperplasia (CAH) is due to an inherited defect in producing cortisol. ACTH may be measured in children suspected of having this condition.Findings suggestive of hypopituitarism (usually due to a benign tumour that reduces pituitary gland secretion) include loss of appetite, tiredness, irregular menstrual cycle, hypogonadism (lower levels of sex hormones), decreased sex drive, frequent nighttime urination, and weight loss. Tumours can also block the nerves controlling vision, causing symptoms such as “tunnel vision” (inability to see things off to the side), loss of vision to some localised areas, and double vision and headaches.
