What might cause elevated specific gravity in a urine sample?

Elevated specific gravity in a urine sample is primarily associated with dehydration because it indicates that the urine is concentrated due to a reduced volume of water in the body. When a person is dehydrated, the kidneys conserve water, leading to the production of more concentrated urine. As a result, substances such as urea and electrolytes become more concentrated, which increases the specific gravity measurement.

In contrast, excessive fluid intake or overhydration would dilute the urine, resulting in a lower specific gravity. Similarly, excessive urination typically leads to less concentrated urine because it often occurs in conditions where the body is trying to rid itself of excessive fluids, again contributing to a decrease in specific gravity. Therefore, the correct identification of dehydration as the cause of elevated specific gravity is grounded in the physiological response of the kidneys to conserve water and maintain homeostasis in the body.