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

Which lesion best characterizes a primary syphilitic chancre?

A combat veteran reports intrusive nightmares, avoids crowded areas, and is hypervigilant. These features are most consistent with which PTSD diagnostic cluster?

A 75-year-old with a new blowing holosystolic murmur at the apex and orthopnea likely has which valvular consequence of ventricular remodeling?

Why does invasive cervical cancer most commonly arise at the transformation zone?

A 48-year-old develops tea-colored urine after a “rhabdo”-level workout in heat. He has diffuse myalgias and weakness. What lab constellation fits best?

A 38-year-old with colicky flank pain radiating to the groin is suspected to have a ureteral stone. Which immediate pathophysiologic change occurs proximal to the obstruction?

A 74-year-old on sertraline presents with headache, nausea, gait unsteadiness, and Na⁺ 122 mEq/L. Serum osmolality is low; urine osmolality is high. Exam shows no edema. Which diagnosis best fits?

A 49-year-old woman with fatigue, weight gain, cold intolerance, and a firm, non-tender goiter is found to have elevated TSH and low free T4. Which serology best supports the most likely diagnosis?

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?