Which term refers to "increased thirst" as a symptom?

Polydipsia refers specifically to an abnormal increase in thirst, often associated with various medical conditions, such as diabetes mellitus or diabetes insipidus. This term is key in recognizing how the body signals a need for more water intake, which can be crucial in diagnosing underlying health issues.

The other terms, while related to fluid balance or levels within the body, denote different concepts. Polyuria describes increased urination, which may lead to dehydration and consequently trigger increased thirst, but it does not directly refer to the sensation of thirst itself. Hypovolemia indicates a decreased volume of blood in the body, which can prompt thirst but is not synonymous with the experience of thirst. Hypernatremia refers to elevated sodium levels in the blood; while it can lead to thirst as a compensatory mechanism, it does not define the condition of increased thirst. Hence, polydipsia is the term that accurately describes the symptom of increased thirst.