Final answer:
The medical term for excessive thirst is Polydipsia (option B), which can occur in various conditions, including diabetes insipidus and diabetes mellitus, often due to hormonal imbalances or high blood glucose levels.
Step-by-step explanation:
The medical term for excessive thirst, or craving large amounts of liquid, is B) Polydipsia. Polydipsia is a condition characterized by frequent intake of water, often as a result of frequent urination. This can sometimes be seen in conditions like diabetes insipidus or diabetes mellitus, where there is an imbalance in the production or function of antidiuretic hormone (ADH), or due to the body's cells being unable to access glucose, leading to dehydration and increased thirst.
Polyuria, on the other hand, refers to the production of an abnormally large volume of urine in a given period, which can be a symptom of diabetes or may result from the use of diuretics or consumption of excessive caffeine or alcohol. Hyponatremia and hypernatremia are conditions related to low and high blood sodium levels respectively, often associated with symptoms different from polydipsia.