Which of these symptoms are also characteristic of diabetes insipidus?
a. polyphagia
b. polyuria
c. polydipsia
d. both polyuria and polyphagia
e. both polyuria and polydipsia
The correct answer and explanation is:
The correct answer is e. both polyuria and polydipsia.
Diabetes insipidus (DI) is a condition characterized by the kidneys’ inability to conserve water, leading to excessive urine production (polyuria) and excessive thirst (polydipsia). These symptoms occur due to a deficiency or resistance to antidiuretic hormone (ADH), which regulates the body’s fluid balance.
Polyuria refers to the production of large amounts of urine. In DI, the kidneys are unable to concentrate urine due to insufficient ADH. This leads to the excretion of large volumes of dilute urine. Patients with DI can produce up to 20 liters of urine per day, compared to the normal range of 1 to 2 liters. This excess urination causes dehydration, prompting the body to signal the need for more fluid.
Polydipsia is the excessive thirst that often accompanies polyuria. As a result of the large fluid losses from urination, the body signals an intense need for hydration, leading individuals with DI to drink large amounts of water. The thirst is typically unrelenting, and individuals with DI may consume several liters of water daily in an attempt to compensate for the fluid loss.
On the other hand, polyphagia, or excessive hunger, is not a typical symptom of diabetes insipidus. Polyphagia is more commonly associated with diabetes mellitus, a different condition in which the body cannot properly regulate blood sugar levels. In diabetes mellitus, the body may not effectively utilize glucose for energy, leading to a sensation of hunger despite adequate food intake.
In summary, the hallmark symptoms of diabetes insipidus are polyuria and polydipsia, and these are the correct answer choices for this question.