Anemia Hematology / Blood System • Anemia: Hgb <13.5 g/dL (men) or <12 g/dL (women). Classified by MCV: microcytic (iron deficiency), normocytic (chronic disease, AKI, blood loss), macrocytic (B12/folate). Identify and treat cause. Chronic Kidney Disease Renal / Urinary System • CKD is kidney damage or GFR <60 mL/min/1.73m² for ≥3 months. Staged G1-G5 by GFR and A1-A3 by albuminuria. Complications: anemia, bone disease, hyperkalemia, hypertension, CVD. Sickle Cell Disease Hematology / Blood System • SCD: hemoglobin S polymerization causing RBC sickling, hemolytic anemia, vaso-occlusion, and organ damage. Hydroxyurea reduces crises. Voxelotor and crizanlizumab are newer agents. Sinus Tachycardia Cardiovascular System • Sinus tachycardia (HR >100) is almost always a secondary response — treat the underlying cause (pain, fever, hypovolemia, anxiety, anemia, PE).