Hаrоld Bооts is а 70-yeаr-old male, who has a history of Type 2 diabetes & Hypertension. He presents to the office with complaints of fatigue, malaise, and pruritus. His wife reports that he has been increasingly irritable & has trouble concentrating to the point that he is frustrated by his usual daily crossword puzzle. His testing shows a glomerular filtration rate (GFR)