Adrenal and Pituitary Disorders
Addison's, Cushing's, pheochromocytoma, SIADH and diabetes insipidus
| Addison's disease (too little cortisol and aldosterone) | Cushing's syndrome (too much cortisol) | |
|---|---|---|
| Signs | Fatigue, weight loss, hypotension, bronze hyperpigmentation, salt craving, nausea | Moon face, buffalo hump, central obesity, thin arms and legs, purple striae, bruising, weakness, mood changes, poor wound healing |
| Labs | ↓ Na⁺, ↑ K⁺, ↓ glucose | ↑ glucose, ↓ K⁺, ↑ Na⁺; hypertension |
| Treatment | Hydrocortisone (larger morning dose) + fludrocortisone; stress dosing during illness; emergency injection kit; medical ID | Most often from steroid medication: taper if possible; otherwise surgery (pituitary or adrenal) or medication |
| Nursing | Fluids, salt intake; never miss doses | Infection prevention, glucose checks, fall and fracture prevention, skin care |
Adrenal (Addisonian) crisis
Severe hypotension or shock, vomiting, abdominal pain, confusion, fever. Triggered by stress, infection, surgery, or stopping steroids suddenly.
→ IV hydrocortisone (e.g., 100 mg) immediately + IV fluids (saline with dextrose); treat the cause.
→ IV hydrocortisone (e.g., 100 mg) immediately + IV fluids (saline with dextrose); treat the cause.
Pheochromocytoma
Adrenal tumor releasing adrenaline: episodes of severe hypertension, headache, sweating, palpitations. Don't palpate the abdomen (can trigger a surge). Before surgery: alpha blocker first, then beta blocker. Primary aldosteronism: hypertension + low K⁺; spironolactone or surgery.
SIADH vs. diabetes insipidus
| SIADH (too much ADH) | Diabetes insipidus (too little ADH effect) | |
|---|---|---|
| Water | Retained: weight gain without edema | Lost: huge volumes of urine (3–20 L/day), extreme thirst |
| Serum sodium | Low (dilutional) | High |
| Urine | Concentrated: high specific gravity | Dilute: specific gravity <1.005 |
| Causes | Small cell lung cancer, brain injury, pneumonia, drugs (SSRIs, carbamazepine) | Head injury, pituitary surgery (central); lithium (kidney type) |
| Treatment | Fluid restriction; hypertonic saline (slowly) if severe symptoms; vaptans; seizure precautions; daily weight | Central: desmopressin (watch for low Na⁺, weight gain). Kidney type: thiazide, stop lithium. Replace fluids |
New names (2022): central DI = arginine vasopressin deficiency (AVP-D); nephrogenic DI = AVP resistance (AVP-R). Updated
Memory hook
SIADH: "Soaked": holding water, sodium diluted. DI: "Dry": peeing it all out, sodium concentrated.
Addison's: add the hormones back. Cushing's: cushion of fat from too much cortisol.
Addison's: add the hormones back. Cushing's: cushion of fat from too much cortisol.