No More Confusion: Osmosis vs. Tonicity

We have all heard the human body is 60% water and we have all heard all the jokes generated from this information (1). It’s more than just a joke; dosing a drug depends on the amount of water in the body and that amount changes depending on age and gender. Water is able to flow freely through cells and distributes itself until the water concentration is even everywhere. The two terms we use to describe the movement of water are osmosis and tonicity. Osmosis and tonicity are often confused, but I’ll explain them in a way that you will never get them mixed up again.