What defines metabolic alkalosis?

Metabolic alkalosis is defined by an increase in base bicarbonate in the body, which leads to an elevated blood pH—typically above the normal range of 7.35-7.45. This condition results from an excess of bicarbonate (HCO₃⁻) or a loss of hydrogen ions (H⁺), which can occur due to various factors such as prolonged vomiting, overuse of diuretics, or specific endocrine disorders.

In metabolic alkalosis, the body's compensatory mechanisms may attempt to restore normal acid-base balance. This includes respiratory compensation through hypoventilation to retain carbon dioxide (CO₂), which can react with water in the body to form carbonic acid (H₂CO₃) and lead to an increase in acidity, thereby countering the alkalosis. The key takeaway is the focus on an actual increase in bicarbonate concentration, which is a defining characteristic of this condition, leading to the resultant high pH level.