Acid and alkali loads
| Acid loads |
| CO2: Respiratory acidosis |
| Nonvolatile acids: Metabolic acidosis |
| Exogenous acids (e.g., salicylate, methanol, and ethylene glycol) |
| Pathologic endogenous acids (e.g., ketoacids and lactic acid) |
| Decreased renal acid excretion (e.g., renal failure and distal renal tubular acidosis) |
| Loss of alkali, equivalent to acid load |
| Gastrointestinal losses (e.g., diarrhea) |
| Urine losses (e.g., proximal renal tubular acidosis) |
| Alkali loads |
| Excess CO2 exhalation: Respiratory alkalosis |
| Nonvolatile alkali: Metabolic alkalosis |
| Exogenous alkali (e.g., NaHCO3 administration) |
| Loss of acid, equivalent to alkali load |
| Gastrointestinal losses (e.g., gastric fluid) |
| Excess urine H+ losses and renal production of new HCO3− (most classic causes of metabolic alkalosis, including chloride depletion metabolic alkalosis and mineralocorticoid excess) |