Metabolic Alkalosis can be classified according to pathophysiology, etiology and chloride responsiveness or urinary chloride concentration.

• 1.The following classification of Metabolic Alkalosis is based on Pathophysiology^[1]:

• 2.The classification based on etiologies are following:

• Chloride depletion or Gastrointestinal loss of hydrogen
  • GI loss: Vomiting (most commonly seen in pyloric stenosis), NG suction , Zollinger-ellison syndrome, Bulimia.^[2]
  • Diuretics: Loop and thiazide diuretics.
  • Diarrhea: Villous adenoma^[3], congenital chloride diarrhea^[4]
  • Cystic fibrosis.^[5]
  • Chloride deficient infant formula.
  • Gastrocystoplasty ^[6]
  • Post hypercapneic metabolic alkalosis.
• Potassium depletion or Mineralocorticoids excess or Renal loss of hydrogen
  • Dietary potassium depletion.^[7]
  • Primary hyperaldosteronism: Conn syndrome or adenoma, hyperplasia, carcinoma, renin or glucocorticoid responsive.
  • Secondary hyperaldosteronism: Reno vascular hypertension, edema (cirrhosis, heart failure, nephrotic syndrome), juxtaglomerular cell(renin producing) tumor, renal cell carcinoma, hemangiopericytoma, nephroblastoma
  • Mineralocorticoid excess due to primary decorticosterone excess (11 beta, 17 alpha hydroxylase deficiency), licorice(glycyrrhetinic acid), liddle syndrome.^{[8] [9]}
  • Bartter and Gitelman syndrome. ^[10]
  • Laxative
• Reduced Glomerular filtration rate
  • Chronic kidney disease
• ECF volume depletion/ Volume contraction
  • Hypovolemia or massive diuresis with loop diuretics.
• Miscellanous
  • Hypercalcemia due to Milk-alkali syndrome or bone metastasis.
  • Massive blood transfusion.
  • Acetate containing colloid sollution.
  • Exogenous alkali admintration.
  • Combined antacid and cation exchange resin administration.
  • Sodium penicillins.