Solutions and Concentration

Water is the universal solvent meaning the most substances (polar and ionic) can dissolve into it.  The substances that are dissolved are called solutes.  A concentration is the amount of a solute that is dissolved in a given amount of water.  The more solute dissolved, the higher the concentration and the less solute dissolved, the lower the concentration.  In the body, you will see concentrations measured in osmolarity which will carry the mOsm label.  In the medical world, you may see solutions measured as a percentage.