Thyroid, Adrenal and the Water Hormones

📖 Terms in this lesson

Addisonian crisis: Profound hypotension and shock from adrenal insufficiency, often triggered by illness, stress or abruptly stopped steroids; treated with IV hydrocortisone.

Thyroid storm: A life-threatening surge of thyroid hormone with high fever, severe tachycardia and agitation.

Myxedema coma: Severe hypothyroidism with hypothermia, bradycardia, hypotension and decreased consciousness.

Diabetes insipidus: Too little antidiuretic hormone, or kidneys that do not respond to it, producing large volumes of dilute urine and a rising sodium.

SIADH: Too much antidiuretic hormone, causing water retention, concentrated urine and a falling sodium.

HOT AND NERVOUS, COLD AND SLUGGISH (thyroid): Hyperthyroidism runs hot and nervous (heat intolerance, weight loss, tachycardia, tremor); hypothyroidism runs cold and sluggish (cold intolerance, weight gain, bradycardia, constipation): the thyroid symptom sorter.

ADDISON'S = ADD, CUSHING'S = CUSHION (adrenal disorders): Addison's is too little cortisol, so ADD steroids (low pressure, low sodium, high potassium); Cushing's is too much, a CUSHION of fat (moon face, high glucose, high pressure).

Free T4 (thyroxine): Free T4 about 0.8 to 1.8 ng/dL (total T4 about 5 to 12 mcg/dL); it is high with a low TSH in hyperthyroidism and low with a high TSH in hypothyroidism, and the levothyroxine dose is adjusted by TSH.

Cortisol (morning serum): About 5 to 25 mcg/dL at 8 AM, lower in the evening; low points to Addison's disease or long-term steroid suppression, high to Cushing's syndrome or stress, and a very low value in shock is an adrenal crisis.

Levothyroxine: Lifelong replacement for hypothyroidism, taken on an empty stomach in the morning, 30 to 60 minutes before food, calcium or iron; too much looks like hyperthyroidism (racing heart, insomnia, weight loss), the dose is set by TSH, and it is never used for weight loss.

Methimazole and propylthiouracil (PTU): Antithyroid drugs for hyperthyroidism that take weeks to work; both can wipe out white cells, so a sore throat or fever is reported immediately, PTU carries a boxed warning for liver failure but is preferred in the first trimester, and methimazole otherwise.

Corticosteroids (prednisone, hydrocortisone, dexamethasone): Suppress inflammation and replace adrenal hormone; expect high glucose, masked infection, fluid retention, bone loss and GI bleeding, give them with food in the morning, never stop abruptly, and give IV hydrocortisone at once for adrenal crisis or when a steroid-dependent client is stressed.