The most common fluid balance tests are potassium and sodium tests. These are the most important salts for body fluids. Both tests are performed on a blood sample. Fluid balance tests do not require fasting or morning sampling. The treating physician is always responsible for interpreting your results.

Name and abbreviation of test: POTASSIUM P -K

The reference range for potassium is 3.3–4.8 mmol/l.

Name and abbreviation of test: SODIUM P -Na

The reference range for sodium is 137–144 mmol/l.