If the medium surrounding the cell has a higher water concentration than the cell, the cell will gain water by osmosis. Such a solution is known as hypotonic solution. If the medium has exactly the same water concentration as the cell, there will be no net movement of water across the cell membrane. Such a solution is known as isotonic solution. If the medium has a lower water concentration then the cell will lose water by osmosis. Such a solution is known as hypertonic solution.