A 24-year-old reports recurrent unilateral, pulsatile head pain lasting 4–72 hours, aggravated by activity and associated with photophobia and nausea. Most likely diagnosis?

A phlebotomist has high-risk percutaneous exposure to HIV from a known viremic patient. Which is the best next step?

A patient avoids leaving the house, fearing inability to escape if panic occurs. This pattern is best described as:

A 61-year-old presents with symmetric swelling and morning stiffness (>1 hour) in MCPs and wrists. Which pathologic process best explains joint damage?

A farmworker exposed to organophosphate insecticides presents with miosis, bronchorrhea/wheezing, bradycardia, salivation, lacrimation, vomiting, and diarrhea. This constellation represents:

A patient presents with 1 week of elevated mood, decreased need for sleep, pressured speech, and distractibility. Which neurotransmitter dysregulation is most implicated?

A nursing student sustains a percutaneous needle exposure from a patient known to be HBsAg-positive; she is unvaccinated. What is the best immediate approach?

A 62-year-old with advanced dementia is asked to copy a simple design. He repeatedly draws the same line over and over despite prompts to stop. This behavior best represents:

A 26-year-old presents with secondary amenorrhea and galactorrhea. Pregnancy test is negative. Which medication most likely explains her elevated prolactin?

A 22-year-old with episodic cough/wheeze has spirometry: FEV₁/FVC 0.64; post-albuterol FEV₁ ↑14% and 250 mL. What is the most consistent interpretation?