Final answer:
Excessive water loss from a red blood cell leads to crenation, where the cell shrinks and may die due to a hypertonic surrounding solution.
Step-by-step explanation:
When excessive amounts of water leave a red blood cell, the condition that occurs is known as crenation. The cell shrinks and collapses due to the movement of water out of the cell into a surrounding solution with a higher concentration of solutes, known as a hypertonic solution. This osmotic imbalance results in the cytosol becoming denser, which interferes with the diffusion necessary for the cell to function properly, potentially leading to cell death.