ABG Basics: Key Values to Know An ABG (arterial blood gas) shows how well the lungs and kidneys manage the body’s acid–base balance * pH tells you how acidic or basic the blood is. Normal: 7.35–7.45 * CO₂ is controlled by the lungs. More CO₂ = more acidic Normal: 35–45 mmHg * HCO₃ (bicarb) is managed by the kidneys. More bicarb = more basic Normal: 22–26 mEq/L Memory trick: Think “lungs over kidneys” and drop the 7s from the pH to help remember the values. Comment below if you would like to see