*Renal Tubular Acidosis (RTA)* *How to approach the scenario?* If the scenario gives you *Urine pH + Normal Anion Gap Metabolic Acidosis* = Consider *RTA* ✅ Also *Granular Muddy Brown Casts* = *RTA* *Do you know?* There are *3 Types* of RTA: 👉 RTA Type *1* 👉 RTA Type *2* 👉 RTA Type *4* *[* *Remember:* There is *NO* RTA Type *3* *]* *How to Differentiate between the RTA Types?* 👉 Look for *Urinary pH* 👉 Look for *Serum K+ Levels* *Urinary pH > 5.5* = Type *1* RTA (Distal RTA) *Serum K+ Inc.* = Type *4* RTA (Hyperkalemic Tubular Acidosis) *Urine pH < 5.5 + Serum K+ low* = Type *2* RTA (Proximal RTA) *Causes of RTA:* Type *1* RTA = *AutoImmune Diseases* (SLE, Sjogren Syndrome) Type *2* RTA = *Fanconi Syndrome*, *Multiple Myeloma* Type *4* RTA = *Hypoaldosteronism* or *Aldosterone resistance*, [Anything that causes a *decrease in Aldosterone* = ACEi , ARBs, Aliskiren, Aldosterone Antagonists (Spironolactone)]