Metabolic acidosis (normal anion-gap): causes

With hyperkalemia: RAISE K+:

RTA type 4
Aldosterone or mineralocorticord deficiency
Iatrogenic: NH4Cl, HCl
"Stenosis": obstructive uropathy
Early uremia
· With hypokalemia: ReDUCE K+:
Renal TA type 1 and 2
Diarrhoea
Urine diversion into gut
Carbonate anhydrase inhibitor
Ex-hyperventilation