Endocrine and Reproductive Disorders Practice Questions
20 free Endocrine and Reproductive Disorders practice questions for the USMLE Step 1. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
A 12-year-old boy presents with polyuria, weight loss, and fatigue. Labs show hyperglycemia and low C-peptide levels. Which condition is most likely?
- A Type 2 diabetes mellitus
- B Type 1 diabetes mellitus
- C MODY2
- D Secondary diabetes from glucocorticoid use
Correct answer: Type 1 diabetes mellitus
Type 1 diabetes is characterized by autoimmune destruction of β-cells, leading to insulin deficiency and low C-peptide levels. It commonly presents in childhood.
A patient with type 2 diabetes has hyperosmolar hyperglycemic state (HHS). Which laboratory finding is expected?
- A Kussmaul respirations
- B High serum ketone levels
- C Normal arterial pH
- D Low serum osmolality
Correct answer: Normal arterial pH
HHS involves profound dehydration and hyperosmolarity with minimal ketosis, so pH is usually normal. It is common in older adults with type 2 diabetes.
A patient presents with heat intolerance, palpitations, and tremor. Labs reveal low TSH and elevated T3/T4. What is the most likely diagnosis?
- A Hypothyroidism
- B Graves disease
- C Hashimoto thyroiditis
- D Subacute (De Quervain) thyroiditis
Correct answer: Graves disease
Graves disease is an autoimmune hyperthyroidism with elevated T3/T4 and suppressed TSH. Symptoms include tachycardia, tremor, and heat intolerance.
A woman presents with irregular menses and hirsutism. Labs show elevated LH:FSH ratio. Which condition is most likely?
- A Primary ovarian insufficiency
- B Polycystic ovarian syndrome
- C Hyperprolactinemia
- D Cushing syndrome
Correct answer: Polycystic ovarian syndrome
PCOS is characterized by an elevated LH:FSH ratio, hyperandrogenism, and menstrual irregularities. Insulin resistance is also common.
A woman at 32 weeks gestation presents with hypertension and proteinuria. Which condition is suspected?
- A Eclampsia
- B Gestational diabetes
- C Preeclampsia
- D HELLP syndrome
Correct answer: Preeclampsia
Preeclampsia presents with new-onset hypertension and proteinuria after 20 weeks of pregnancy. It can progress to eclampsia if seizures occur.
A patient with hypothyroidism shows high TSH and low T3/T4. What is the most likely mechanism?
- A Pituitary failure
- B Thyroid gland failure
- C TSH receptor activation
- D Excess iodine intake
Correct answer: Thyroid gland failure
Primary hypothyroidism presents with low thyroid hormones and elevated TSH due to pituitary compensation. Hashimoto thyroiditis is a common cause.
A pregnant woman develops painless vaginal bleeding at 34 weeks. Ultrasound shows placenta covering the cervical os. Which condition is this?
- A Placental abruption
- B Placenta previa
- C Vasa previa
- D Uterine rupture
Correct answer: Placenta previa
Placenta previa involves painless bleeding and placenta covering the cervical os. It requires careful monitoring and often C-section delivery.
A patient with diabetes develops microalbuminuria. Which drug slows progression of diabetic nephropathy?
- A Calcium channel blockers
- B ACE inhibitors
- C Beta-blockers
- D Thiazide diuretics
Correct answer: ACE inhibitors
ACE inhibitors decrease intraglomerular pressure and reduce proteinuria. They slow progression of diabetic kidney disease.
A woman presents with galactorrhea and amenorrhea. Labs show elevated prolactin. What is the most likely cause?
- A Pituitary adenoma
- B Hypothyroidism
- C Pregnancy
- D Dopamine agonist therapy
Correct answer: Pituitary adenoma
Prolactinomas are common pituitary tumors causing hyperprolactinemia, leading to galactorrhea and amenorrhea. Dopamine inhibits prolactin release.
A patient with diabetic ketoacidosis presents with rapid deep breathing. What is this respiratory pattern called?
- A Cheyne–Stokes respirations
- B Kussmaul respirations
- C Biot breathing
- D Apneustic breathing
Correct answer: Kussmaul respirations
Kussmaul respirations are rapid, deep breaths used to compensate for metabolic acidosis in DKA. They help blow off CO₂.
A patient with hyperthyroidism undergoes radioactive iodine ablation. Which complication may occur?
- A Permanent hypothyroidism
- B Acute adrenal crisis
- C Hyperprolactinemia
- D Syndrome of inappropriate ADH
Correct answer: Permanent hypothyroidism
Radioactive iodine frequently causes permanent hypothyroidism due to destruction of thyroid tissue. Lifelong thyroid hormone replacement is common.
A sexually active woman presents with lower abdominal pain and cervical motion tenderness. What is the most likely diagnosis?
- A Ruptured ectopic pregnancy
- B Pelvic inflammatory disease
- C Pelvic endometriosis
- D Ovarian cyst torsion
Correct answer: Pelvic inflammatory disease
PID commonly presents with lower abdominal pain and cervical motion tenderness (chandelier sign). It is often caused by Chlamydia or Gonorrhea.
A patient with hyperthyroidism has exophthalmos and pretibial myxedema. What is the underlying mechanism?
- A Fibroblast activation via TSH receptors
- B Excess cortisol hormone production
- C Congenital TSH hormone deficiency
- D Decreased β-adrenergic receptor activity
Correct answer: Fibroblast activation via TSH receptors
Graves disease involves TSH receptor–mediated fibroblast activation, increasing glycosaminoglycans in the orbit and skin. This causes exophthalmos and myxedema.
A woman presents with infertility and dyspareunia. Ultrasound shows ectopic endometrial tissue. Which condition is this?
- A Adenomyosis
- B Endometriosis
- C Leiomyoma
- D Asherman syndrome
Correct answer: Endometriosis
Endometriosis involves endometrial tissue outside the uterus, causing pain and infertility. Sites include ovaries and pelvic peritoneum.
A diabetic patient presents with numbness in both feet. What is the most likely mechanism?
- A Segmental demyelination
- B Sorbitol accumulation in nerves
- C Acetylcholine receptor antibodies
- D Hypocalcemia
Correct answer: Sorbitol accumulation in nerves
Chronic hyperglycemia leads to sorbitol accumulation in Schwann cells, causing neuropathy. This results in distal symmetric polyneuropathy.
A patient with hypothyroidism shows periorbital edema. What causes this finding?
- A Increased cortisol secretion
- B Glycosaminoglycan accumulation
- C Reduced plasma renin levels
- D Increased aldosterone secretion
Correct answer: Glycosaminoglycan accumulation
In hypothyroidism, mucopolysaccharide deposition causes nonpitting edema (myxedema). This commonly affects the face and eyelids.
A woman taking oral contraceptives presents with mild hypertension. What is a known effect of estrogen?
- A Increased aldosterone production
- B Decreased hepatic angiotensinogen
- C Inhibition of renin release
- D Reduced renal sodium retention
Correct answer: Increased aldosterone production
Estrogen increases hepatic angiotensinogen production, activating the RAAS system and increasing blood pressure. This is a known side effect of OCPs.
A patient presents with fatigue, constipation, and cold intolerance. Labs reveal low T3/T4 and low TSH. Which condition is most likely?
- A Primary hypothyroidism
- B Secondary hypothyroidism
- C Graves disease
- D Thyroid storm
Correct answer: Secondary hypothyroidism
Low TSH and low T3/T4 indicate secondary (pituitary) hypothyroidism. The pituitary fails to stimulate thyroid hormone production.
A pregnant woman develops painless vaginal bleeding and a 'snowstorm' pattern on ultrasound. Which condition is this?
- A Complete hydatidiform mole
- B Partial hydatidiform mole
- C Placental abruption
- D Choriocarcinoma
Correct answer: Complete hydatidiform mole
A complete mole presents with diffuse swelling of villi, extremely high hCG, and a 'snowstorm' ultrasound pattern. Fetal tissue is absent.
A patient with diabetes presents with retinopathy. What is the primary mechanism?
- A Microaneurysms from vessel glycation
- B Increased intraocular pressure
- C Autoimmune destruction of retinal cells
- D Chronic vitamin A deficiency
Correct answer: Microaneurysms from vessel glycation
Chronic hyperglycemia causes nonenzymatic glycation of basement membranes, leading to microaneurysms and retinal ischemia. This results in diabetic retinopathy.