Final answer:
Osmolality is the ratio of solutes in a fluid. High plasma and urine osmolality can indicate a response to dehydration or fluid imbalance. The woman's high plasma osmolality and urine osmolarity suggests a diagnosis of Diabetes Insipidus, which causes excessive water loss through the urine.
Step-by-step explanation:
Osmolality is a measure of the total concentration of solutes in a fluid. In the context of medicine, high plasma and urine osmolality can indicate a response by the body to a state of dehydration or other changes in fluid balance. This woman's high plasma osmolality of 300 mosm/liter and urine osmolarity of 1200 mosm/liter could indicate a diagnosis of Diabetes Insipidus, a condition in which the kidneys are not able to properly conserve water due to a lack of antidiuretic hormone (ADH) or a response to this hormone. ADH controls the amount of water reabsorbed by the kidneys, and in its absence, a large volume of dilute urine is produced, known as polyuria. This typically leads to thirst and excessive intake of fluids, known as polydipsia. The high osmolarity in the urine suggests that the kidneys are still able to concentrate the urine in an attempt to conserve water, which is consistent with Diabetes Insipidus.
Learn more about Diabetes Insipidus