North Carolina EMT State Practice Exam 2026 - Free EMT Practice Questions and Study Guide

Dehydration is characterized by a decrease in total body water, which is particularly common in elderly patients. As people age, they may experience a natural decline in their body’s water content due to various factors such as reduced sensation of thirst, changes in kidney function, and often inadequate fluid intake. These changes can make older adults more susceptible to dehydration, especially in hot weather or during illness.

In the elderly, dehydration can have significant effects on health, including impairing cognitive function, causing dizziness or confusion, and increasing the risk of falls. It can also complicate the management of chronic illnesses that are prevalent in this age group.

The other conditions mentioned, such as obesity, kidney failure, and heart disease, can have varying impacts on hydration status but do not primarily reflect a straightforward decrease in total body water like dehydration does. Obesity, for example, typically involves increased body fat and may not correlate with total body water decrease. Kidney failure can lead to fluid retention rather than dehydration, and heart disease can affect fluid balance but is not solely defined by decreased total body water.