Hypo-hydration is a state of an inadequate amount of water required for normal functioning of the body. In other words, it is a body water content beyond normal. It also refers to the status with a maximum urine osmolality.
Severe hypo-hydration occurs when the water loss accounts for more than 10% of the body weight and can cause organ failure and death.
Mild hypo-hydration occurs when the water loss accounts for 1-2% of the body weight. (1)