It has been asserted that the criterion method to
assess hydration status is measurement of serum
osmolality.2,11 Sampling blood for osmolality is both
invasive and inconvenient, and may take a significant
amount of time to complete testing. For these
reasons, urine color is often used as an index of hydration
status, particularly in field settings such as
military maneuvers and sporting events. While this
technique may help to identify dehydration, it is also
highly variable and affected by several factors