NCLEX Endocrine System Practice Questions with Detailed Rationales

🩸 Introduction

The endocrine system plays a vital role in regulating hormones that control metabolism, growth, reproduction, and stress responses. For NCLEX candidates, understanding this system is crucial, as many questions focus on disorders such as diabetes mellitus, hypothyroidism, hyperthyroidism, Addison’s disease, and Cushing’s syndrome.

This practice set includes 100 NCLEX-style endocrine system questions with rationales, designed to help you analyze, apply, and evaluate nursing knowledge effectively. Each question mirrors real NCLEX complexity — from prioritization to medication administration.

🧠 Part 1: NCLEX Endocrine System Questions (1–25)

1. A client with Graves’ disease presents with weight loss, tremors, and heat intolerance. What is the most appropriate nursing intervention?
A. Provide a cool environment
B. Encourage high-calorie meals
C. Restrict fluids
D. Limit iodine intake
✅ Correct Answer: A
Rationale: Hyperthyroidism increases metabolism and body heat. Providing a cool environment helps reduce discomfort.

2. A patient on levothyroxine should be instructed to take the medication:
A. With food
B. At bedtime
C. On an empty stomach in the morning
D. With calcium supplements
✅ Correct Answer: C
Rationale: Levothyroxine absorption is best on an empty stomach. Food and calcium interfere with absorption.

3. The nurse recognizes which symptom as a sign of hypoglycemia?
A. Flushed skin and dry mouth
B. Tremors and confusion
C. Deep, rapid respirations
D. Polyuria
✅ Correct Answer: B
Rationale: Low blood sugar causes sympathetic activation — tremors, anxiety, sweating, and confusion.

4. Which lab finding indicates Addison’s disease?
A. High sodium, low potassium
B. Low sodium, high potassium
C. High cortisol
D. Elevated glucose
✅ Correct Answer: B
Rationale: Addison’s disease causes adrenal insufficiency — leading to hyponatremia and hyperkalemia.

5. The nurse caring for a patient with SIADH should monitor for:
A. Dehydration
B. Hypernatremia
C. Hyponatremia
D. Increased urine output
✅ Correct Answer: C
Rationale: SIADH leads to water retention, diluting sodium and causing hyponatremia.

5. The nurse caring for a patient with SIADH should monitor for:
A. Dehydration
B. Hypernatremia
C. Hyponatremia
D. Increased urine output
✅ Correct Answer: C
Rationale: SIADH causes excessive release of ADH, leading to water retention and dilutional hyponatremia.

6. Which of the following is a priority intervention for a client with myxedema coma?
A. Administer IV thyroid hormone replacement
B. Provide a low-calorie diet
C. Encourage ambulation
D. Withhold oxygen therapy
✅ Correct Answer: A
Rationale: Myxedema coma is a medical emergency caused by severe hypothyroidism; IV levothyroxine and supportive care are lifesaving.

7. A client with Cushing’s syndrome may show which laboratory result?
A. Low sodium and low glucose
B. High sodium and high glucose
C. Low cortisol levels
D. Elevated potassium
✅ Correct Answer: B
Rationale: Cushing’s syndrome involves excessive cortisol, leading to hypernatremia, hyperglycemia, and hypokalemia.

8. Which nursing instruction is most important for a patient receiving radioactive iodine therapy?
A. Share utensils to promote exposure
B. Sleep close to family members
C. Avoid close contact with others for several days
D. Take medication with milk
✅ Correct Answer: C
Rationale: Patients excrete radioactive iodine through body fluids; minimizing contact prevents radiation exposure to others.

9. A patient with hypoparathyroidism is at risk for which complication?
A. Hypercalcemia
B. Hypocalcemia
C. Hyperglycemia
D. Hypokalemia
✅ Correct Answer: B
Rationale: The parathyroid gland regulates calcium levels; low PTH decreases calcium, leading to tetany and muscle cramps.

10. Which finding suggests thyroid storm?
A. Bradycardia and fatigue
B. Hypothermia and confusion
C. High fever and tachycardia
D. Weight gain and cold intolerance
✅ Correct Answer: C
Rationale: Thyroid storm is a life-threatening condition marked by hypermetabolism—fever, tachycardia, and hypertension.

11. The nurse teaches a patient with Addison’s disease to:
A. Avoid sodium
B. Double corticosteroid dose during stress
C. Discontinue steroids if feeling well
D. Reduce potassium intake
✅ Correct Answer: B
Rationale: During stress or illness, cortisol demand increases. Patients must double their dose to prevent adrenal crisis.

12. The best indicator of diabetes insipidus improvement is:
A. Increased urine output
B. Decreased serum sodium
C. Decreased urine output
D. Weight loss
✅ Correct Answer: C
Rationale: Diabetes insipidus causes polyuria; treatment success is reflected by decreased urine output and stable electrolytes.

13. Which hormone deficiency causes dwarfism?
A. Growth hormone (GH)
B. Thyroxine (T4)
C. Insulin
D. Aldosterone
✅ Correct Answer: A
Rationale: A deficiency in GH during childhood leads to stunted physical growth—pituitary dwarfism.

14. The nurse suspects hypothyroidism when a patient reports:
A. Insomnia and anxiety
B. Weight gain and cold intolerance
C. Increased appetite and heat intolerance
D. Tremors and palpitations
✅ Correct Answer: B
Rationale: Decreased thyroid hormone slows metabolism, causing fatigue, weight gain, and intolerance to cold.

15. Which test is most specific for diagnosing Cushing’s syndrome?
A. Serum sodium
B. 24-hour urinary cortisol test
C. Random blood glucose
D. Serum ACTH
✅ Correct Answer: B
Rationale: Elevated 24-hour urinary cortisol confirms hypercortisolism, the hallmark of Cushing’s syndrome.

16. The nurse caring for a patient with pheochromocytoma should avoid:
A. Giving fluids
B. Palpating the abdomen
C. Administering antihypertensives
D. Monitoring BP
✅ Correct Answer: B
Rationale: Palpation can trigger catecholamine release from the adrenal tumor, causing severe hypertension.

17. Which diet is appropriate for hyperthyroidism?
A. Low-calorie, high-fiber
B. High-calorie, high-protein
C. Low-fat, high-sodium
D. High-fat, low-carb
✅ Correct Answer: B
Rationale: Patients have increased metabolism and need extra calories and protein to prevent weight loss.

18. Post-thyroidectomy, the nurse should keep which item at the bedside?
A. Oxygen
B. Suction equipment
C. Tracheostomy set
D. IV fluids
✅ Correct Answer: C
Rationale: Airway obstruction due to edema or hematoma is a serious complication; a tracheostomy set must be available.

19. The nurse notes positive Chvostek’s and Trousseau’s signs. This indicates:
A. Hypercalcemia
B. Hypocalcemia
C. Hyponatremia
D. Hyperkalemia
✅ Correct Answer: B
Rationale: These are classic signs of hypocalcemia, often seen in hypoparathyroidism or post-thyroid surgery.

20. Which finding is expected in diabetes insipidus?
A. Low urine specific gravity
B. High urine osmolarity
C. Decreased serum sodium
D. Weight gain
✅ Correct Answer: A
Rationale: DI causes excessive water loss, resulting in dilute urine with low specific gravity (<1.005).

21. Which nursing diagnosis is priority for a client with hyperparathyroidism?
A. Risk for fluid deficit
B. Risk for injury related to bone demineralization
C. Impaired gas exchange
D. Ineffective airway clearance
✅ Correct Answer: B
Rationale: Excess PTH increases calcium levels, pulling calcium from bones and causing fractures.

22. The nurse expects which symptom in Cushing’s syndrome?
A. Weight loss
B. Thin extremities and moon face
C. Hypotension
D. Hyperpigmentation
✅ Correct Answer: B
Rationale: Cortisol excess leads to fat redistribution, muscle wasting, and characteristic “moon face” and “buffalo hump.”

23. Which hormone regulates calcium and phosphate balance?
A. Insulin
B. Aldosterone
C. Parathyroid hormone (PTH)
D. Epinephrine
✅ Correct Answer: C
Rationale: PTH increases calcium reabsorption and reduces phosphate reabsorption in the kidneys.

24. Which of the following findings is most concerning for a patient with Addisonian crisis?
A. Low BP and confusion
B. Weight gain and bradycardia
C. Hypertension and fever
D. Elevated glucose and calmness
✅ Correct Answer: A
Rationale: Addisonian crisis leads to severe hypotension, electrolyte imbalance, and shock—requires emergency care.

25. A client with SIADH is placed on fluid restriction. Which assessment best indicates treatment effectiveness?
A. Weight loss and improved sodium levels
B. Increased urine output
C. Decreased thirst
D. Normal potassium
✅ Correct Answer: A
Rationale: Weight loss and corrected sodium levels indicate proper management of water retention.

NCLEX Endocrine System Practice Questions (26–50) with Rationales

Q26. A nurse is teaching a patient newly diagnosed with type 1 diabetes about insulin administration. Which statement indicates a need for further teaching?
A. “I can mix regular and NPH insulin in the same syringe.”
B. “I will rotate injection sites to avoid lipodystrophy.”
C. “I can skip my insulin if I am not eating.”
D. “I should check my blood sugar before each meal.”

Correct Answer: C. “I can skip my insulin if I am not eating.”
Rationale: Even if not eating, the body needs basal insulin to prevent hyperglycemia and ketoacidosis. Skipping insulin is unsafe.

Q27. A patient with SIADH is receiving fluid restriction. Which lab result requires immediate attention?
A. Sodium 118 mEq/L
B. Sodium 135 mEq/L
C. Potassium 4.2 mEq/L
D. Calcium 9.0 mg/dL

Correct Answer: A. Sodium 118 mEq/L
Rationale: Severe hyponatremia (<120 mEq/L) can cause seizures and neurological damage; requires prompt intervention.

Q28. A client with Cushing’s syndrome asks why they have purple stretch marks. The nurse responds:
A. “They are caused by high levels of cortisol breaking down skin tissue.”
B. “They are due to vitamin C deficiency.”
C. “They happen from excess salt in your diet.”
D. “They result from low blood sugar.”

Correct Answer: A. “They are caused by high levels of cortisol breaking down skin tissue.”
Rationale: Excess cortisol causes collagen breakdown and skin thinning, leading to purple striae (stretch marks).

Q29. Which test is most reliable for diagnosing diabetes mellitus?
A. Random blood sugar
B. Oral glucose tolerance test
C. Fasting blood sugar
D. Hemoglobin A1c

Correct Answer: D. Hemoglobin A1c
Rationale: HbA1c reflects average blood glucose over 2–3 months and is the most accurate indicator for long-term glucose control.

Q30. A nurse observes Chvostek’s sign in a post-thyroidectomy patient. This indicates:
A. Hypocalcemia
B. Hypercalcemia
C. Hypokalemia
D. Hyponatremia

Correct Answer: A. Hypocalcemia
Rationale: Chvostek’s sign (facial twitching when tapping facial nerve) signals low calcium, often due to parathyroid injury during thyroid surgery.

Q31. Which finding would the nurse expect in a patient with Addisonian crisis?
A. High blood pressure
B. Low potassium
C. Severe hypotension
D. Low blood sugar

Correct Answer: C. Severe hypotension
Rationale: In Addisonian crisis, cortisol and aldosterone deficiency cause vascular collapse and hypotension; immediate corticosteroid therapy is vital.

Q32. A nurse is educating a patient with hyperparathyroidism. Which dietary advice is appropriate?
A. Increase calcium intake
B. Avoid foods high in phosphorus
C. Eat high-sodium foods
D. Avoid fluids

Correct Answer: B. Avoid foods high in phosphorus
Rationale: Hyperparathyroidism causes elevated calcium; high phosphorus foods worsen calcium imbalance.

Q33. Which endocrine disorder is treated with radioactive iodine therapy?
A. Hypothyroidism
B. Hyperthyroidism
C. Cushing’s syndrome
D. Addison’s disease

Correct Answer: B. Hyperthyroidism
Rationale: Radioactive iodine destroys overactive thyroid cells, reducing excessive hormone production in hyperthyroidism.

Q34. The nurse expects which symptom in a patient with hypothyroidism?
A. Increased appetite
B. Restlessness
C. Cold intolerance
D. Weight loss

Correct Answer: C. Cold intolerance
Rationale: Decreased metabolism in hypothyroidism causes intolerance to cold, fatigue, and weight gain.

Q35. A diabetic patient presents with confusion, sweating, and slurred speech. What is the nurse’s first action?
A. Give insulin
B. Provide orange juice
C. Administer glucagon
D. Start IV fluids

Correct Answer: B. Provide orange juice
Rationale: These are signs of hypoglycemia; providing fast-acting carbohydrates like juice quickly restores blood sugar.

Q36. Which hormone deficiency results in dwarfism?
A. Growth hormone
B. Thyroid hormone
C. Cortisol
D. Insulin

Correct Answer: A. Growth hormone
Rationale: Insufficient growth hormone in childhood leads to stunted growth and dwarfism.

Q37. A nurse caring for a patient on long-term corticosteroids should instruct the patient to:
A. Stop medication suddenly if symptoms improve
B. Increase potassium intake
C. Avoid vaccines
D. Reduce salt in diet

Correct Answer: B. Increase potassium intake
Rationale: Corticosteroids can cause hypokalemia; patients should consume potassium-rich foods.

Q38. A patient with pheochromocytoma will likely have which symptom?
A. Hypotension
B. Bradycardia
C. Severe hypertension
D. Hypoglycemia

Correct Answer: C. Severe hypertension
Rationale: Pheochromocytoma causes excess catecholamine release, resulting in severe episodic hypertension.

Q39. The nurse suspects diabetic ketoacidosis (DKA) when the patient presents with:
A. Bradycardia
B. Fruity breath odor
C. Hypoglycemia
D. Cold clammy skin

Correct Answer: B. Fruity breath odor
Rationale: Ketone accumulation in DKA causes fruity-smelling breath, deep respiration, and dehydration.

Q40. The primary cause of secondary hypothyroidism is:
A. Pituitary dysfunction
B. Autoimmune thyroiditis
C. Iodine deficiency
D. Radiation exposure

Correct Answer: A. Pituitary dysfunction
Rationale: Secondary hypothyroidism results from inadequate TSH secretion by the pituitary gland.

Q41. Which nursing diagnosis is most appropriate for a patient with Cushing’s syndrome?
A. Fluid volume deficit
B. Risk for infection
C. Hypothermia
D. Activity intolerance due to fatigue

Correct Answer: B. Risk for infection
Rationale: Excess cortisol suppresses immune function, increasing susceptibility to infection.

Q42. A patient taking desmopressin should be monitored for:
A. Dehydration
B. Water intoxication
C. Hyperglycemia
D. Hypokalemia

Correct Answer: B. Water intoxication
Rationale: Desmopressin causes water retention; overuse may lead to dilutional hyponatremia and water intoxication.

Q43. What is the effect of parathyroid hormone (PTH)?
A. Decreases calcium absorption
B. Increases calcium levels in blood
C. Inhibits bone resorption
D. Decreases phosphate excretion

Correct Answer: B. Increases calcium levels in blood
Rationale: PTH increases serum calcium by stimulating bone resorption and enhancing calcium reabsorption by the kidneys.

Q44. A patient with Cushing’s syndrome may develop which metabolic disturbance?
A. Hypoglycemia
B. Hyperglycemia
C. Hyponatremia
D. Hypocalcemia

Correct Answer: B. Hyperglycemia
Rationale: Cortisol promotes gluconeogenesis, raising blood glucose levels in Cushing’s syndrome.

Q45. Which medication is used to treat hypothyroidism?
A. Methimazole
B. Levothyroxine
C. Propylthiouracil
D. Radioactive iodine

Correct Answer: B. Levothyroxine
Rationale: Levothyroxine replaces deficient thyroid hormone in hypothyroidism, improving metabolism and energy.

Q46. Which lab finding supports the diagnosis of diabetic ketoacidosis (DKA)?
A. pH 7.45
B. Serum glucose 110 mg/dL
C. Ketones in urine
D. Bicarbonate 26 mEq/L

Correct Answer: C. Ketones in urine
Rationale: DKA causes fat breakdown for energy, producing ketones that appear in urine and cause metabolic acidosis.

Q47. A patient is prescribed metformin. Which instruction is most important?
A. Take with meals
B. Take before bedtime
C. Skip dose if eating less
D. Avoid fluids

Correct Answer: A. Take with meals
Rationale: Taking metformin with food reduces gastrointestinal side effects and enhances absorption.

Q48. Which of the following symptoms indicates diabetic neuropathy?
A. Blurred vision
B. Tingling in the feet
C. Rapid heart rate
D. Constipation

Correct Answer: B. Tingling in the feet
Rationale: Nerve damage from chronic high glucose causes numbness or tingling, especially in lower extremities.

Q49. Which condition results from excessive secretion of growth hormone before puberty?
A. Dwarfism
B. Gigantism
C. Acromegaly
D. Cretinism

Correct Answer: B. Gigantism
Rationale: Excess growth hormone before growth plate closure causes excessive bone growth and gigantism.

Q50. Which finding indicates effective treatment of hypothyroidism?
A. Weight gain
B. Decreased energy
C. Normal heart rate and temperature
D. Persistent fatigue

Correct Answer: C. Normal heart rate and temperature
Rationale: Successful levothyroxine therapy restores metabolic balance, resulting in normal pulse, temperature, and energy levels.

🧠 NCLEX Endocrine System Practice Questions (51–75) with Detailed Rationales

Q51. A nurse is assessing a patient with hypothyroidism. Which symptom would the nurse expect?
A. Heat intolerance
B. Tachycardia
C. Constipation
D. Weight loss

✅ Correct Answer: C. Constipation
Rationale: Slowed metabolism in hypothyroidism reduces gastrointestinal motility, leading to constipation and bloating.

Q52. A nurse teaches a patient with Addison’s disease about corticosteroid therapy. Which statement shows correct understanding?
A. “I will stop the medicine if I gain weight.”
B. “I must take this medication for the rest of my life.”
C. “I can skip my dose when I feel well.”
D. “I’ll take my medicine only during flare-ups.”

✅ Correct Answer: B. “I must take this medication for the rest of my life.”
Rationale: Addison’s disease causes lifelong adrenal insufficiency, requiring continuous corticosteroid replacement.

Q53. Which finding is consistent with hyperglycemia?
A. Tremors and sweating
B. Polyuria and blurred vision
C. Headache and confusion
D. Shallow respirations

✅ Correct Answer: B. Polyuria and blurred vision
Rationale: Elevated blood glucose causes osmotic diuresis (polyuria) and fluid shifts that blur vision.

Q54. Which nursing action is appropriate for a patient with diabetes insipidus (DI)?
A. Restrict fluids
B. Monitor for dehydration
C. Encourage diuresis
D. Reduce sodium intake

✅ Correct Answer: B. Monitor for dehydration
Rationale: DI causes excessive urine output due to lack of ADH, leading to dehydration and electrolyte imbalance.

Q55. A nurse monitors for which symptom of myxedema coma?
A. Hyperthermia
B. Hypertension
C. Bradycardia and hypothermia
D. Restlessness

✅ Correct Answer: C. Bradycardia and hypothermia
Rationale: Myxedema coma, a severe hypothyroidism complication, causes dangerously low heart rate and body temperature.

Q56. Which patient teaching is most important for someone prescribed radioactive iodine?
A. “Avoid close contact with pregnant women or children.”
B. “Take medication with milk.”
C. “Stop thyroid medication immediately.”
D. “Expect diarrhea for several days.”

✅ Correct Answer: A. “Avoid close contact with pregnant women or children.”
Rationale: Radioactive iodine emits radiation; close contact should be avoided for several days to prevent exposure to others.

Q57. The nurse expects which ECG change in a patient with hyperkalemia due to Addison’s disease?
A. Flattened T waves
B. U waves
C. Peaked T waves
D. Short PR interval

✅ Correct Answer: C. Peaked T waves
Rationale: Elevated potassium levels cause peaked T waves and risk for cardiac arrhythmias.

Q58. A nurse notes that a patient with Cushing’s syndrome has fragile skin and bruises easily. What is the cause?
A. Vitamin K deficiency
B. Decreased collagen from high cortisol
C. High calcium levels
D. Excess aldosterone

✅ Correct Answer: B. Decreased collagen from high cortisol
Rationale: Cortisol excess causes protein breakdown and skin thinning, leading to easy bruising.

Q59. Which instruction should the nurse give a diabetic patient taking insulin before exercise?
A. “Skip your next insulin dose.”
B. “Eat a snack before exercising.”
C. “Increase insulin dose.”
D. “Exercise before checking blood glucose.”

✅ Correct Answer: B. “Eat a snack before exercising.”
Rationale: Physical activity lowers blood sugar; a carbohydrate snack prevents hypoglycemia.

Q60. Which clinical feature differentiates diabetic ketoacidosis (DKA) from hyperosmolar hyperglycemic state (HHS)?
A. Presence of ketones
B. High blood glucose
C. Dehydration
D. Altered mental status

✅ Correct Answer: A. Presence of ketones
Rationale: DKA is associated with ketone production and metabolic acidosis, unlike HHS.

Q61. Which gland secretes antidiuretic hormone (ADH)?
A. Thyroid gland
B. Posterior pituitary
C. Adrenal medulla
D. Pancreas

✅ Correct Answer: B. Posterior pituitary
Rationale: ADH (vasopressin) is secreted by the posterior pituitary and regulates water balance by acting on kidneys.

Q62. The nurse should expect which finding in a patient with hypoparathyroidism?
A. Muscle twitching
B. Weight gain
C. Hypertension
D. Diarrhea

✅ Correct Answer: A. Muscle twitching
Rationale: Hypocalcemia from low PTH leads to neuromuscular irritability — tetany and muscle twitching.

Q63. What is the main action of insulin?
A. Increases blood glucose
B. Converts glycogen to glucose
C. Promotes glucose uptake into cells
D. Inhibits fat synthesis

✅ Correct Answer: C. Promotes glucose uptake into cells
Rationale: Insulin lowers blood sugar by helping glucose enter body cells for energy.

Q64. Which symptom suggests diabetic retinopathy?
A. Chest pain
B. Vision changes
C. Increased urination
D. Tremors

✅ Correct Answer: B. Vision changes
Rationale: Prolonged hyperglycemia damages retinal blood vessels, causing blurred vision or vision loss.

Q65. The nurse anticipates which lab value in a patient with SIADH?
A. Low urine specific gravity
B. High serum sodium
C. Low serum osmolality
D. Increased urine output

✅ Correct Answer: C. Low serum osmolality
Rationale: In SIADH, water retention dilutes blood, leading to low serum osmolality and hyponatremia.

Q66. A nurse provides dietary education to a patient with hypothyroidism. Which food should be avoided?
A. Seafood
B. Soy products
C. Fruits
D. Poultry

✅ Correct Answer: B. Soy products
Rationale: Soy interferes with thyroid hormone absorption and should be limited in hypothyroid patients.

Q67. A patient with adrenal insufficiency is at greatest risk for which complication?
A. Fluid overload
B. Hypovolemic shock
C. Hypertension
D. Hyperglycemia

✅ Correct Answer: B. Hypovolemic shock
Rationale: Lack of aldosterone causes sodium and water loss, leading to severe dehydration and shock.

Q68. Which nursing priority applies to a patient with hyperthyroidism?
A. Maintain warm environment
B. Encourage rest and quiet surroundings
C. Provide high-fiber diet
D. Restrict fluid intake

✅ Correct Answer: B. Encourage rest and quiet surroundings
Rationale: Hyperthyroidism increases metabolism and anxiety; calm environments help prevent overstimulation.

Q69. Which finding is most concerning in a diabetic patient?
A. Tingling in feet
B. Slow wound healing on the foot
C. Increased appetite
D. Blurred vision

✅ Correct Answer: B. Slow wound healing on the foot
Rationale: Poor circulation and neuropathy in diabetes delay wound healing, risking infection and amputation.

Q70. Which hormone increases blood glucose levels?
A. Insulin
B. Glucagon
C. Thyroxine
D. Calcitonin

✅ Correct Answer: B. Glucagon
Rationale: Glucagon, released by pancreatic alpha cells, raises blood glucose by stimulating glycogen breakdown.

Q71. Which intervention is most important after thyroid surgery?
A. Monitor for bleeding
B. Monitor urine output
C. Encourage early ambulation
D. Provide high-calorie diet

✅ Correct Answer: A. Monitor for bleeding
Rationale: Post-thyroidectomy, bleeding may compress the airway — a life-threatening complication.

Q72. The nurse suspects a pituitary tumor when a patient reports:
A. Polyuria and polydipsia
B. Weight loss
C. Increased libido
D. Hypotension

✅ Correct Answer: A. Polyuria and polydipsia
Rationale: Pituitary dysfunction can cause diabetes insipidus due to reduced ADH secretion.

Q73. Which teaching is crucial for a patient prescribed prednisone?
A. “Stop the drug immediately if you feel better.”
B. “Take with food to reduce stomach irritation.”
C. “Take at bedtime for better absorption.”
D. “Avoid all salt intake.”

✅ Correct Answer: B. “Take with food to reduce stomach irritation.”
Rationale: Corticosteroids can cause gastric irritation and ulcers; taking with food prevents complications.

Q74. Which symptom suggests hypoglycemia in a diabetic patient?
A. Hot, dry skin
B. Sweating and dizziness
C. Deep, rapid respirations
D. Fruity breath odor

✅ Correct Answer: B. Sweating and dizziness
Rationale: Low blood sugar triggers sympathetic response — sweating, tremors, palpitations, and confusion.

Q75. A patient with thyroid storm will most likely exhibit:
A. Bradycardia
B. Hypothermia
C. Severe tachycardia and fever
D. Weight gain

✅ Correct Answer: C. Severe tachycardia and fever
Rationale: Thyroid storm is a life-threatening hyperthyroid crisis with extreme tachycardia, hyperthermia, and agitation.

NCLEX Endocrine System Questions (76–100)

76. A client with Addison’s disease is prescribed hydrocortisone. Which instruction is most important for the nurse to give?

A. Take the medication only when you feel weak
B. Double the dose if you miss a dose
C. Do not stop the medication abruptly
D. Take the drug on an empty stomach

✅ Answer: C. Do not stop the medication abruptly
Rationale: Stopping corticosteroids suddenly can lead to adrenal crisis due to suppressed adrenal function. Doses must be tapered gradually under medical supervision.

77. The nurse notes that a patient with hyperthyroidism has bulging eyes. What is the correct term for this condition?

A. Ptosis
B. Exophthalmos
C. Myxedema
D. Diplopia

✅ Answer: B. Exophthalmos
Rationale: Exophthalmos (protrusion of the eyeballs) is a classic sign of Graves’ disease due to autoimmune inflammation behind the eyes.

78. Which finding would indicate that levothyroxine therapy is effective?

A. Decreased heart rate
B. Weight gain
C. Increased energy levels
D. Decreased appetite

✅ Answer: C. Increased energy levels
Rationale: Levothyroxine restores normal thyroid hormone levels, which increase metabolism and energy.

79. Which lab result supports a diagnosis of hypothyroidism?

A. High T3 and T4, low TSH
B. Low T3 and T4, high TSH
C. Low T3, high T4, normal TSH
D. Normal T3 and T4, high TSH

✅ Answer: B. Low T3 and T4, high TSH
Rationale: The pituitary increases TSH secretion when thyroid hormones are low, characteristic of primary hypothyroidism.

80. The nurse suspects hypoglycemia in a diabetic patient taking insulin. Which symptom supports this?

A. Dry skin
B. Confusion and tremors
C. Increased urination
D. Fruity breath odor

✅ Answer: B. Confusion and tremors
Rationale: Hypoglycemia causes neurological symptoms such as confusion, shakiness, and irritability due to low glucose supply to the brain.

81. A patient with Cushing’s syndrome would likely have which appearance?

A. Thin face and limbs
B. Moon face and truncal obesity
C. Hyperpigmented skin
D. Enlarged thyroid gland

✅ Answer: B. Moon face and truncal obesity
Rationale: Cushing’s syndrome results from excess cortisol, leading to fat redistribution to the face, neck, and trunk.

82. A diabetic patient is sweating and confused. The nurse should first:

A. Call the physician
B. Give 4 oz of orange juice
C. Administer glucagon
D. Check urine ketones

✅ Answer: B. Give 4 oz of orange juice
Rationale: Orange juice provides quick glucose for hypoglycemia relief when the patient is conscious.

83. Which hormone regulates calcium and phosphorus balance?

A. Insulin
B. Parathyroid hormone
C. Aldosterone
D. Cortisol

✅ Answer: B. Parathyroid hormone
Rationale: PTH maintains calcium and phosphorus balance by acting on bones, kidneys, and intestines.

84. A client with diabetes insipidus has polyuria and polydipsia. Which medication will help manage the condition?

A. Desmopressin
B. Insulin
C. Metformin
D. Prednisone

✅ Answer: A. Desmopressin
Rationale: Desmopressin is a synthetic form of ADH that reduces urine output and manages diabetes insipidus.

85. Which dietary recommendation should be given to a patient with hypothyroidism?

A. High-calorie, high-protein diet
B. Low-sodium diet
C. High-fiber, low-calorie diet
D. Low-iodine diet

✅ Answer: A. High-calorie, high-protein diet
Rationale: Hypothyroid patients have a slowed metabolism, so they need a diet that supports energy levels and prevents fatigue.

86. A client with type 1 diabetes reports feeling dizzy after exercise. What is the likely cause?

A. Hyperglycemia
B. Hypoglycemia
C. Lactic acidosis
D. Dehydration

✅ Answer: B. Hypoglycemia
Rationale: Exercise increases insulin sensitivity and glucose utilization, leading to hypoglycemia if snacks are not taken before or after.

87. The nurse should monitor which lab value for a patient taking levothyroxine?

A. Serum sodium
B. Serum potassium
C. TSH level
D. Calcium

✅ Answer: C. TSH level
Rationale: TSH is used to monitor thyroid replacement effectiveness—elevated TSH indicates under-replacement.

88. Which complication can occur from untreated hyperparathyroidism?

A. Hypocalcemia
B. Kidney stones
C. Tetany
D. Muscle spasms

✅ Answer: B. Kidney stones
Rationale: Excess PTH increases calcium reabsorption, which can cause hypercalcemia and calcium-based kidney stones.

89. A diabetic patient asks why foot care is so important. The nurse explains:

A. “It helps prevent swelling.”
B. “It reduces infection risk from poor circulation.”
C. “It helps you lose weight.”
D. “It controls your blood sugar.”

✅ Answer: B. It reduces infection risk from poor circulation.
Rationale: Diabetes damages peripheral circulation and sensation, increasing the risk of unnoticed wounds and infections.

90. A patient is prescribed propylthiouracil (PTU) for hyperthyroidism. Which finding should be reported immediately?

A. Weight gain
B. Fever or sore throat
C. Mild fatigue
D. Hair loss

✅ Answer: B. Fever or sore throat
Rationale: These signs may indicate agranulocytosis, a rare but serious adverse effect of PTU.

91. Which sign indicates a thyroid storm?

A. Bradycardia
B. Hypotension
C. Hyperthermia and tachycardia
D. Weight gain

✅ Answer: C. Hyperthermia and tachycardia
Rationale: Thyroid storm causes excessive thyroid hormone release, resulting in dangerously high fever and heart rate.

92. The nurse teaches a diabetic client about “sick day” management. Which instruction is correct?

A. Stop taking insulin when not eating
B. Check blood glucose more frequently
C. Drink less fluid
D. Avoid testing urine for ketones

✅ Answer: B. Check blood glucose more frequently
Rationale: Illness can raise blood glucose, requiring closer monitoring and possible insulin adjustments.

93. Which endocrine disorder is treated with lifelong hormone replacement therapy?

A. Cushing’s syndrome
B. Addison’s disease
C. Hyperthyroidism
D. Diabetes insipidus

✅ Answer: B. Addison’s disease
Rationale: Addison’s involves adrenal insufficiency, requiring lifelong corticosteroid replacement.

94. Which lab value is most important to monitor for a patient on insulin therapy?

A. Hemoglobin
B. Potassium
C. Calcium
D. Bilirubin

✅ Answer: B. Potassium
Rationale: Insulin shifts potassium into cells, risking hypokalemia especially in high-dose therapy.

95. Which condition results from excessive growth hormone secretion after epiphyseal closure?

A. Gigantism
B. Acromegaly
C. Dwarfism
D. Addison’s disease

✅ Answer: B. Acromegaly
Rationale: Acromegaly occurs in adults when GH remains elevated, leading to enlarged hands, feet, and facial bones.

96. A diabetic patient has a blood glucose of 500 mg/dL with ketones in the urine. What should the nurse anticipate?

A. Administration of oral antidiabetic drugs
B. Administration of IV insulin and fluids
C. Encourage rest and fluids at home
D. Give a sugary snack

✅ Answer: B. Administration of IV insulin and fluids
Rationale: This is diabetic ketoacidosis (DKA), requiring IV insulin and hydration to correct metabolic imbalance.

97. Which hormone is secreted by the adrenal medulla?

A. Cortisol
B. Aldosterone
C. Epinephrine
D. ACTH

✅ Answer: C. Epinephrine
Rationale: The adrenal medulla releases epinephrine and norepinephrine during stress (“fight or flight” response).

98. The nurse should instruct a diabetic patient to carry which item for emergencies?

A. Glucagon kit or glucose tablets
B. Insulin syringe
C. Diabetic ID card only
D. Low-sugar snack

✅ Answer: A. Glucagon kit or glucose tablets
Rationale: These provide rapid treatment for hypoglycemia when immediate sugar intake is required.

99. What is the function of aldosterone?

A. Increases blood glucose
B. Regulates sodium and potassium balance
C. Decreases inflammation
D. Promotes calcium absorption

✅ Answer: B. Regulates sodium and potassium balance
Rationale: Aldosterone promotes sodium reabsorption and potassium excretion to maintain blood pressure and fluid balance.

100. A patient is receiving radioactive iodine therapy for hyperthyroidism. Which teaching is appropriate?

A. Avoid close contact with family for a few days
B. Take extra calcium supplements
C. Limit fluid intake
D. Stop all thyroid medications immediately

✅ Answer: A. Avoid close contact with family for a few days
Rationale: Radioactive iodine temporarily emits radiation, so maintaining distance minimizes exposure risk to others.

🧭 Explore More NCLEX Practice Topics

To strengthen your NCLEX preparation, don’t stop here. Master every key nursing domain with our free and in-depth MCQ practice sets — each designed with real exam-style questions and rationales 👇

🩸 NCLEX Fluid & Electrolytes Practice Questions – Understand body balance, dehydration, and IV therapy concepts in detail.
💊 NCLEX Medication Calculations Practice Questions – Sharpen your drug dosage calculation skills to perfection.
🩹 NCLEX Wound Care Practice Questions – Learn how to manage surgical wounds, burns, and infection prevention.
🧠 NCLEX Pharmacology Questions – Focus on brain, nerves, and neurological emergencies.
🩺 NCLEX Diabetes Management Questions – Practice the most repeated insulin, glucose, and patient education questions.
🧬 NCLEX Oncology Nursing Practice Questions – Build strong oncology and chemotherapy nursing knowledge.

📘 Bonus: Visit our NCLEX Master Library for topic-wise quizzes covering cardiac, renal, respiratory, and endocrine systems — all 100% free with detailed rationales.

🏁 Conclusion

Mastering the Endocrine System is vital for every NCLEX candidate because hormonal balance impacts nearly every body function. By practicing these 100 Endocrine System NCLEX questions with rationales, you strengthen your understanding of conditions like diabetes, hypothyroidism, hyperthyroidism, and adrenal disorders — all of which are frequently tested on the NCLEX exam.

To maximize your score:

Review each rationale to understand why the correct answer is right.
Link related systems like fluid balance, medications, and diabetes management, since the NCLEX often combines them in clinical scenarios.
Keep revisiting Tayari MCQs for new, updated quizzes every week — written to match the latest NCLEX test plan.

💡 Pro Tip: Bookmark this page and practice at least 10 questions daily. Consistency builds both accuracy and confidence for your NCLEX success!🩸 Introduction

🧠 Part 1: NCLEX Endocrine System Questions (1–25)

5. The nurse caring for a patient with SIADH should monitor for:
A. Dehydration
B. Hypernatremia
C. Hyponatremia
D. Increased urine output
✅ Correct Answer: C
Rationale: SIADH causes excessive release of ADH, leading to water retention and dilutional hyponatremia.

NCLEX Endocrine System Practice Questions (26–50) with Rationales