Electrolytes & Minerals
Sodium, potassium, calcium, magnesium and the other salts that keep fluid balance, nerves and muscles working.
13 tests explained
Most common tests
- Bicarbonate (Total CO2)Bicarbonate, often printed as CO2 or total CO2, gives a clue about your body's acid-base balance. It is part of most routine blood panels.
- Calcium, TotalTotal calcium is the amount of calcium in your blood. It supports your nerves, muscles, heart and bones, and it is on most routine panels.
- ChlorideChloride is a salt mineral in your blood. It works with sodium to balance fluids and acid, and it is part of the basic and comprehensive metabolic panels.
- MagnesiumMagnesium is a mineral your muscles, nerves and heart need. A blood test shows only a small part of your body's total supply.
- PotassiumPotassium is a mineral that helps your nerves, muscles and heart work. This test shows how much is in your blood.
- SodiumSodium is the main salt in your blood. This test shows how well your body balances water and salt.
Common follow-up tests
- Anion GapThe anion gap is a calculation from sodium, chloride and bicarbonate that helps clinicians look into the acid-base balance of your blood.
- Calcium, Corrected for AlbuminCorrected calcium adjusts your total calcium for a low or high albumin level, to estimate what total calcium would be with a typical amount of albumin.
- Calcium, IonizedIonized calcium is the free, active part of the calcium in your blood. It is checked when total calcium or protein levels make the usual test hard to read.
- Magnesium, RBCMagnesium measured inside your red blood cells. Some clinicians use it to look at magnesium stores, but how well it reflects your whole-body magnesium is debated.
- Osmolality, CalculatedCalculated osmolality is an estimate of how concentrated your blood is, worked out from your sodium, glucose and BUN results rather than measured directly.
- Osmolality, SerumSerum osmolality shows how concentrated your blood is: how many dissolved particles, mostly sodium, glucose and urea, it holds per kilogram of fluid.
- Phosphorus (Phosphate)Phosphorus is a mineral that builds bones and powers cells. Its blood level mostly reflects your kidneys, parathyroid glands, vitamin D and diet.