What term describes excessive thirst?

The term that describes excessive thirst is polydipsia. This condition often indicates an underlying health issue, such as diabetes mellitus, where the body experiences increased levels of glucose in the blood (hyperglycemia), leading to greater fluid loss and a corresponding increase in thirst.

Understanding polydipsia is important in evaluating symptoms and conditions related to fluid balance and may prompt further investigation into potential causes such as dehydration or hormonal imbalances.

The other terms provided relate to different medical conditions: atelectasis refers to the partial or complete collapse of a lung, hyperglycemia denotes high blood sugar levels, and oliguria indicates a decreased output of urine. Each of these terms addresses distinct physiological issues that are not related to the sensation of thirst.