What symptom is characterized by excessive thirst?

Polydipsia is the term specifically used to describe excessive thirst. It is often a symptom associated with various conditions, including diabetes mellitus, where elevated blood sugar levels lead to frequent urination (polyuria) and subsequent dehydration, triggering a heightened sense of thirst. Understanding polydipsia is essential because it reflects the body's mechanism to restore fluid balance when it is lost due to excessive urination or other factors.

Polyuria refers to the increased frequency of urination, which, while related, does not directly describe the symptom of thirst itself. The terms hypoglycemia and hyperglycemia pertain to low and high blood sugar levels, respectively, and while they can lead to symptoms such as altered thirst, they are not specifically defined by the symptom of excessive thirst. Thus, polydipsia is the most accurate descriptor for this specific symptom of excessive thirst.