10 exam-style questions with answers and explanations, straight from our 1,030-question bank. Tap an answer to check yourself. When you're ready, take the scored version in the free practice test.
The Endocrinology exam has 300 questions and runs 7 hours.
These 10 free Endocrinology questions are organized by exam domain, so you can see how each part of the Certification in Endocrinology blueprint is tested. Reveal the answer and explanation under each question.
Domain 1: Principles of endocrinology, hormones, physiology (4-8%)
Question 1
A cortisol evaluation yields a discordant result in a woman taking an estrogen-containing oral contraceptive: serum total cortisol is 3.4 micrograms/dL after 1 mg of overnight dexamethasone, while two late-night salivary cortisol measurements and two complete 24-hour urinary free cortisol collections are normal. Dexamethasone exposure is adequate, and her sleep schedule is regular. Which effect of oral estrogen most directly explains the isolated total-cortisol abnormality?
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Correct answer: D - Increased cortisol-binding globulin raises total cortisol without corresponding free-cortisol excess
Domain 2: Diabetes mellitus (13-17%)
Question 2
After two days of vomiting and minimal food intake, a 58-year-old man taking empagliflozin for type 2 diabetes develops abdominal pain and deep, rapid breathing. Plasma glucose is 176 mg/dL, beta-hydroxybutyrate 5.6 mmol/L, venous pH 7.23, bicarbonate 12 mmol/L, and potassium 4.2 mmol/L. Kidney function is preserved. Empagliflozin has been stopped and isotonic fluid resuscitation started. Which treatment should now be added?
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Correct answer: B - Intravenous insulin with concurrent dextrose and close electrolyte monitoring
Question 3
At 26 weeks of gestation, a patient without previously diagnosed diabetes undergoes a fasting 75-g oral glucose tolerance test using the one-step approach. Plasma glucose is 88 mg/dL fasting, 171 mg/dL at one hour, and 167 mg/dL at two hours. How should these results change her care?
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Correct answer: C - Diagnose gestational diabetes and begin nutrition therapy with glucose monitoring
During a supervised fast, a woman without diabetes becomes confused at a laboratory plasma glucose of 43 mg/dL; the confusion resolves after intravenous glucose. The pretreatment sample shows insulin 4.8 microU/mL (laboratory fasting reference 2-25), C-peptide 1.4 ng/mL, proinsulin 18 pmol/L, and beta-hydroxybutyrate 0.2 mmol/L. A contemporaneous sulfonylurea/meglitinide screen is negative, and renal and hepatic function are normal. Which mechanism is supported by this critical sample?
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Correct answer: D - Inappropriately persistent endogenous insulin secretion
Domain 7: Tumors of the thyroid (1-5%)
Question 5
A 44-year-old woman has cytologically confirmed papillary thyroid carcinoma measuring 1.7 cm in the right lobe. Ultrasound shows a solitary intrathyroidal lesion, a normal left lobe, and no suspicious cervical lymph nodes. There is no evidence of gross extrathyroidal extension or distant disease, and she has no familial thyroid cancer or prior neck irradiation. She has elected surgical treatment. Under the 2025 American Thyroid Association guideline, what is the preferred initial operation?
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Correct answer: D - Right thyroid lobectomy alone
Domain 8: Disorders of the ovaries/breast (3-7%)
Question 6
An outside pelvic ultrasound is reported as showing normal ovaries in a 16-year-old referred for irregular menstruation. Menarche occurred four years ago; cycles have remained 50-80 days apart for the past two years. She has gradually progressive hirsutism and elevated testosterone confirmed with a reliable assay, without virilization. Pregnancy testing, TSH, prolactin, and an appropriate evaluation for nonclassic congenital adrenal hyperplasia are unremarkable. Applying the 2023 international criteria for polycystic ovary syndrome, how should the ultrasound affect the diagnosis?
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Correct answer: C - The menstrual and androgen findings support the diagnosis without abnormal ovarian imaging
Domain 11: Disorders of the adrenal cortex (6-10%)
Question 7
The diagnosis of primary aldosteronism has been established in a 56-year-old man with hypertension and previous spontaneous hypokalemia. Potassium is now 4.0 mmol/L on replacement. Adrenal CT shows a 1.5-cm left adrenal nodule and no right-sided lesion. Cortisol excess and pheochromocytoma have been excluded. He is an operative candidate and would prefer surgery if the aldosterone excess is unilateral. Which investigation is most useful for deciding whether the left gland should be removed?
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Correct answer: B - Perform adrenal venous sampling to assess aldosterone lateralization
At follow-up for persistent acromegaly after pituitary surgery, a patient taking pegvisomant reports less sweating and reduced soft-tissue swelling. IGF-I has fallen from 620 to 195 ng/mL (age-adjusted reference 70-270), but a random GH concentration has risen from 7 to 22 ng/mL. MRI shows unchanged residual tumor, and liver tests are normal. What does this apparent biochemical discordance mean for treatment?
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Correct answer: A - Continue the dose; IGF-I indicates biochemical control during GH-receptor blockade
Before parathyroid surgery is considered, a 38-year-old man is evaluated for calcium concentrations of 10.8-11.1 mg/dL documented since adolescence. His mother has similar results. He has no stones or fragility fractures, adequate calcium intake, normal kidney function, and a 25-hydroxyvitamin D concentration of 36 ng/mL. He takes neither lithium nor a thiazide. Current serum calcium is 11.0 mg/dL, albumin 4.0 g/dL, creatinine 1.0 mg/dL, and PTH 52 pg/mL (reference 15-65). A complete 24-hour urine collection contains 66 mg calcium and 1,500 mg creatinine. Using the calcium/creatinine clearance ratio = (urine calcium x serum creatinine)/(serum calcium x urine creatinine), which interpretation should guide the next decision?
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Correct answer: A - Ratio 0.004; investigate familial hypocalciuric hypercalcemia before pursuing surgery
Domain 17: Bone/Osteoporosis (2-6%)
Question 10
A follow-up DXA report labels a total-hip BMD decrease from 0.800 to 0.780 g/cm2 as "worsening osteoporosis." Both scans were obtained on the same scanner with acceptable positioning. The facility has established a total-hip precision error of 1.5%; its 95% least significant change is calculated as 2.77 x precision error. The patient has taken alendronate correctly for two years, has had no interval fractures, and has no new secondary cause of bone loss. Which conclusion is justified by this comparison?
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Correct answer: B - The 2.5% decrease is below the 4.2% LSC; treatment failure is unproven
The rest of the Endocrinology blueprint
The Endocrinology exam also covers these domains. Drill them in the full free practice test: