A 34-year-old male presents to your clinic with complaints of extreme thirst and frequent urination. He reports drinking over 8 liters of water daily but still feeling thirsty. Often, he craves cold water. His Symptoms began insidiously about a month ago and have progressively worsened. He is particularly worried about a seizure-like shaking he experienced this morning. He denies dysuria, hematuria, or changes in urine color. No fever, chills, or flank pain. He works as an office manager and has not noticed any significant weight loss or changes in appetite. Water Deprivation Test: No significant increase in urine osmolality with water restriction. Later, administration of desmopressin resulted in an increase in urine osmolality to 600 mOsm/kg. As you go over his laboratory results, his high sodium level caught your attention. Which of the following types of hypernatremia is observed in this disorder?
