19.0: Introduction
In a healthy state, the mass of the human body mass is 50 percent to 80 percent water (Lorenzo et al., 2019). The water percentage variances occur because of differences in lean muscle versus fat. Lean muscle consists of approximately 70 percent water, whereas fat is only approximately 10 percent water (Lorenzo et al., 2019). For this reason, even in healthy individuals, age and activity status have a significant impact the risk for excess or deficiency of body water. Young children who have yet to develop significant lean muscle, older adults who have lost lean muscle, and individuals who, for a variety of reasons, have differing levels of lean muscle are at greater risk for a water deficit.
The human body maintains a delicate balance of fluids and electrolytes to help ensure proper functioning and homeostasis. When fluid or electrolyte levels become imbalanced, individuals are at risk for organ system dysfunction. If an imbalance goes undetected and is left untreated, organ systems cannot function properly and, ultimately, death will occur. Nurses must be able to recognize subtle changes in fluid or electrolyte balances in their patients so they can intervene promptly. Timely assessment and intervention prevent complications and save lives.