APEA 3P Test Bank 2025–2026 | 200 High-Yield Pathophysiology
Practice Questions with Answers & Detailed Rationales | NP Boards
Prep | A+ Verified
Question 1: Pathophysiology
A 58-year-old woman presents to the clinic complaining of severe fatigue, unintentional weight
gain, cold intolerance, and constipation over the past 3 months. On physical examination, her
skin is dry, her face appears puffy, and her speech is slow. Vital signs reveal a heart rate of 56
bpm and a blood pressure of 118/76 mmHg. Laboratory studies show elevated thyroid-
stimulating hormone (TSH) and decreased free T4 levels. Which of the following is the most
likely diagnosis?
A. Graves' disease
B. Subclinical hypothyroidism
C. Hashimoto’s thyroiditis
D. Central hypothyroidism
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Answer: C. Hashimoto’s thyroiditis
Rationale: Hashimoto’s thyroiditis is the most common cause of primary hypothyroidism in
iodine-sufficient regions. It is an autoimmune condition resulting in thyroid gland destruction.
Classic symptoms include fatigue, cold intolerance, dry skin, and bradycardia. The elevated TSH
with low free T4 supports a primary thyroid disorder. Graves' disease presents with hyperthyroid
symptoms. Subclinical hypothyroidism has a normal free T4. Central hypothyroidism would
present with low or inappropriately normal TSH and low T4 due to pituitary or hypothalamic
dysfunction.
Question 2: Pathophysiology
A 67-year-old retired coal miner presents with a 6-month history of progressive shortness of
breath, chronic dry cough, and fatigue. He denies recent infections or environmental exposures.
Physical examination reveals inspiratory crackles at the lung bases and digital clubbing. A high-
resolution CT scan shows bilateral reticular opacities and honeycomb changes, especially in the
subpleural regions. Pulmonary function tests reveal a restrictive pattern. The patient has no
history of autoimmune disease, smoking, or occupational exposure to asbestos. Based on the
clinical findings and imaging, what is the most likely diagnosis?
A. Chronic bronchitis
B. Idiopathic pulmonary fibrosis
C. Emphysema
D. Sarcoidosis
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Answer: B. Idiopathic pulmonary fibrosis
Rationale: The hallmark of idiopathic pulmonary fibrosis (IPF) includes a nonproductive cough,
exertional dyspnea, and characteristic honeycombing on CT. The restrictive lung pattern and
absence of other identifiable causes support IPF. Chronic bronchitis is typically associated with
productive cough and smoking. Emphysema involves alveolar destruction and hyperinflation.
Sarcoidosis often shows bilateral hilar lymphadenopathy and granulomas.
Question 3: Pathophysiology
A 49-year-old woman presents to the clinic with fatigue, weight loss, dizziness, and muscle
weakness. She also reports occasional salt cravings and skin darkening around her elbows and
knuckles. Her blood pressure is 90/60 mmHg and her labs reveal hyponatremia (Na+ 128
mmol/L), hyperkalemia (K+ 5.8 mmol/L), and hypoglycemia (glucose 64 mg/dL). A morning
serum cortisol level is low, and ACTH is elevated. She has no history of steroid use or
autoimmune disease. Which electrolyte pattern is most consistent with her diagnosis?
A. Hypernatremia and hypokalemia
B. Hyponatremia and hyperkalemia
C. Hyponatremia and hypokalemia
D. Hypernatremia and hyperkalemia
Answer: B. Hyponatremia and hyperkalemia
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Rationale: Addison’s disease (primary adrenal insufficiency) is characterized by decreased
aldosterone and cortisol, leading to sodium loss (hyponatremia), potassium retention
(hyperkalemia), and low glucose. Increased ACTH can cause hyperpigmentation. This profile
rules out other electrolyte combinations, especially those involving hypernatremia or
hypokalemia, which are more typical in other conditions.
Question 4: Pathophysiology
A 27-year-old woman presents with anxiety, heat intolerance, weight loss despite increased
appetite, and palpitations. She also notes changes in her eyes, including swelling and a sensation
of “grittiness.” On exam, she has a resting pulse of 110 bpm, a fine tremor in her hands, and
bilateral exophthalmos. Her neck is diffusely enlarged without nodules or tenderness. Lab studies
reveal low TSH, elevated T3 and T4 levels. What is the most likely underlying laboratory
abnormality?
A. Decreased TSH and elevated T3/T4
B. Elevated TSH and decreased T3/T4
C. Normal TSH and elevated T3/T4
D. Elevated TSH and normal T3/T4
Answer: A. Decreased TSH and elevated T3/T4
Rationale: The patient presents with signs of hyperthyroidism, likely Graves’ disease. In
primary hyperthyroidism, excess thyroid hormone suppresses TSH via negative feedback. The