Cushing's Syndrome is an IMPORTANT disease!

Hyposecretion of adrenal steroids - Addison's disease

This is an uncommon disease since both adrenal glands must suffer a 90% loss of function before symptoms appear. In 25% of the cases, degeneration of the adrenal cortex is due to chronic TB. Autoimmune destruction of the cortical tissue is believed to be another cause.

Symptoms:

1. Hypoglycemia, hyponatremia (low blood sodium) and hyperkalemia (high blood potassium).
2. Severe dehydration leads to hypovolemia. Low levels of body fluids, especially blood, will cause low blood pressure and can produce cardiac atrophy.
3. Gastrointestinal disorders
4. Low tolerance to stress or trauma
5. Hyperpigmentation due to elevated levels of ACTH in the blood.

Hypersecretion of adrenal steroids - Cushing's syndrome

Chief causes of Cushing's syndrome:

1. Hypersecretion of ACTH - Pituitary Cushing's syndrome is responsible for 60 to 70% of these cases. This condition is brought on by a pituitary adenoma.

2. Hypersecretion of adrenal steroids due to an adenoma of the adrenal cortex (20% of the cases) produces low levels of ACTH by negative feedback. This is called adrenal Cushing's syndrome.

3. Hypersecretion of ACTH by a non-endocrine cancer, e.g., lung carcinoma. This is called paraneoplastic Cushing's syndrome and is responsible for 10 to 15% of the cases.

4. Iatrogenic Cushing's syndrome is due to the long term use of glucocorticoids to control inflammation and edema or autoimmune diseases like rheumatoid arthritis.

Symptoms:

1. Hyperglycemia due to enhanced gluconeogenesis.
2. Catabolism of body protein producing poor wound healing, easy bruising and muscular weakness.
3. Decreased immunity.
4. Hypernatremia leading to excessive water retention.
5. Hyperkalcemia and high blood pressure.
6. Shifting of fat deposits to the face ("moon face") and upper torso ("Buffalo hump").
7. In a male child - Muscular hypertrophy ("pocket Hercules").
8. In a female child or adult - Virilsm (bearded lady).