Endocrinology High-Yield: Diabetes, Thyroid, and Adrenal for FNP Boards
Clinical High-Yield · 10 min read · May 1, 2026
Why Endocrinology Is a Board Goldmine
Endocrinology questions appear consistently across both AANP and ANCC exams. The good news: the boards test a finite set of conditions in predictable ways. Master this framework and you'll pick up points reliably.
Diabetes Mellitus
Diagnosis
- Fasting glucose ≥126 mg/dL on two occasions
- Random glucose ≥200 mg/dL with symptoms
- HbA1c ≥6.5% on two occasions
- 2-hour glucose ≥200 mg/dL on OGTT
Management Hierarchy
First-line: Metformin (unless contraindicated — eGFR <30, contrast dye, liver disease, alcohol use).
Add-on agents — know the board favorites:
- GLP-1 agonists (semaglutide, liraglutide): Weight loss, cardiovascular benefit, injectable. First choice add-on for patients with CVD or obesity.
- SGLT-2 inhibitors (empagliflozin, dapagliflozin): Cardiovascular and renal protection. Risk: UTIs, DKA (rare), Fournier's gangrene.
- Sulfonylureas (glipizide, glimepiride): Cheap, effective, but cause hypoglycemia and weight gain.
- DPP-4 inhibitors (sitagliptin): Weight-neutral, low hypoglycemia risk.
- Insulin: Required for Type 1. Used in Type 2 when other agents fail.
HbA1c Targets
- Most adults: <7%
- Elderly, limited life expectancy, hypoglycemia-prone: <8%
- Tight control in pregnancy: <6.5%
Thyroid Disease
Hypothyroidism
Primary: TSH elevated, free T4 low. Most common cause: Hashimoto's thyroiditis (autoimmune, anti-TPO antibodies).
Treatment: Levothyroxine. Monitor TSH every 6–8 weeks until stable, then annually. Take on empty stomach, 30–60 minutes before food.
Subclinical: TSH elevated, normal free T4. Treat if TSH >10, symptomatic, pregnant, or planning pregnancy.
Hyperthyroidism
Graves' disease: Most common. Diffuse goiter, exophthalmos, pretibial myxedema. TSH suppressed, free T4/T3 elevated. Positive TSI antibodies.
Treatment options: Methimazole (PTU in first trimester), radioactive iodine ablation, thyroidectomy.
Thyroid storm: Emergency. Fever, tachycardia, altered mental status. Treat with PTU, beta-blockers, steroids, iodine (in that order).
Thyroid Nodules
Single nodule: TSH first. If TSH low → thyroid scan. If TSH normal/high → ultrasound. Biopsy if >1 cm with suspicious features.
Adrenal Disorders
Cushing's Syndrome
Excess cortisol. Causes: exogenous steroids (most common), pituitary adenoma (Cushing's disease), adrenal adenoma, ectopic ACTH.
Classic presentation: Central obesity, moon face, buffalo hump, purple striae, hypertension, hyperglycemia, easy bruising, proximal muscle weakness.
Screening: 24-hour urine free cortisol, late-night salivary cortisol, or 1 mg overnight dexamethasone suppression test.
Addison's Disease
Primary adrenal insufficiency. Autoimmune destruction most common cause.
Classic presentation: Fatigue, weight loss, hyperpigmentation (especially skin folds, gums, scars), hypotension, hyponatremia, hyperkalemia.
Diagnosis: Morning cortisol, ACTH stimulation test.
Treatment: Hydrocortisone + fludrocortisone. Stress dosing during illness.
Adrenal crisis: Emergency. Hypotension, vomiting, altered mental status. IV hydrocortisone immediately.
The Board Trick for Endocrine Questions
Most endocrine board questions follow this pattern: abnormal lab → diagnosis → management. Know the diagnostic criteria cold, know the first-line treatment, and know one or two key complications or monitoring parameters for each condition.