Which of the following is a common side effect of diuretics?

Diuretics are medications commonly prescribed to help the body eliminate excess fluid by increasing urine production. This can lead to a significant loss of water and electrolytes, which may result in dehydration. Dehydration is a well-documented side effect of diuretics, as these drugs are designed to promote diuresis—the increased production of urine. When the body loses excessive amounts of fluid, a state of dehydration can occur, leading to symptoms such as dry mouth, dizziness, and fatigue.

In contrast, weight gain, increased appetite, and headaches are less commonly associated with diuretics. While diuretics facilitate fluid loss, weight gain generally occurs due to fluid retention, which is counter to the purpose of diuretics. Increased appetite is not a recognized effect of diuretics and may be influenced by other factors unrelated to their use. Headaches can occur in some individuals but are not a direct or common side effect linked specifically to diuretics. Hence, dehydration stands out as a typical consequence of diuretic treatment, making it the correct answer.