1. UNa<20 or FENa<1%
   1. Hypervolumia
      1. AKI
   2. Hypovolumia
      1. Diuretics
      2. Salt-wasting Nephropathy
      3. mineralcoricoid deficiency
      4. Bicarbonaturia/RTA/Metatbolic alkalosis
   3. Euvolumia
      1. increased ADH
         1. Hypothyrodism
         2. Adrenal insufficiency
         3. SIADH
2. UNa>20 or FENa>1%
   1. Hypovolumia
      1. Extra-renal loss
         1. GI loss
         2. Skin loss
   2. HYpervolumia
      1. Intravascular volume depletion
         1. CHF
         2. Liver cirrhosis
         3. Nephrotic syndrome