Final answer:
A decreased USG indicates a dilute urine, often associated with conditions like diabetes insipidus that result in polyuria, or increased urine production. Urine color is influenced by hydration status, with decreased USG generally leading to lighter colored urine. To treat dehydration, isotonic intravenous fluids are usually administered.
Step-by-step explanation:
A decreased Urine Specific Gravity (USG) in a medical context typically indicates a dilute urine, which can be a sign of conditions that lead to increased urine production. One such condition is diabetes insipidus, where there is a problem with the regulation of the body's water balance, leading to the production of large amounts of dilute urine (polyuria).
The color of urine is determined mainly by urochrome and can indicate different states of hydration, with darker urine generally indicating dehydration and lighter urine indicating overhydration or a less concentrated urine, as would be the case with a decreased USG.
When patients are dehydrated, they are typically given isotonic fluids intravenously, such as saline, to match the concentration of body fluids and help restore proper hydration levels.