What Is an Anion Gap? The anion gap test measures anion gap (sometimes called serum anion gap) or how much acid is in your blood. Acid levels that are higher or lower than normal can tip your doctor ...

The anion gap blood test measures the acid-base and electrolyte balance in the blood. Results can show whether there is an imbalance in a person’s pH levels, which may be making the blood too acidic ...

A barium swallow is a type of test used to look inside the esophagus, or food pipe. A doctor might recommend this test if they need to look at the outline of any part of a person’s digestive system.