Adult Dehydration

Excerpt

Dehydration in adults is a clinically significant condition caused by an imbalance between fluid intake and loss, often leading to disturbances in the balance of total body electrolytes. Although mainstream media frequently claims that 75% of Americans are chronically dehydrated, no scientific evidence in the medical literature supports this assertion. In contrast, dehydration is highly prevalent among older adults, with reported prevalence rates in the United States ranging from 17% to 28%.

Dehydration is often precipitated by low fluid intake, increased fluid loss, or a combination of both of these factors. This is further influenced by factors such as age-related changes, chronic illness, and medication use. The pathophysiological mechanisms include activation of the renin-angiotensin-aldosterone system, increased release of antidiuretic hormone (ADH), and stimulation of the sympathetic nervous system, all of which work to retain fluids and stabilize circulation.

Clinically, dehydration presents with symptoms ranging from mild thirst and fatigue to severe complications such as confusion, hypotension, and multiple organ dysfunction. Dehydration is a common cause of hospital admissions, contributing to significant morbidity and mortality while often complicating a range of medical conditions. Dehydration is primarily diagnosed clinically, with laboratory investigations, including serum electrolytes, serum osmolality, and renal function tests, providing supportive information. Treatment focuses on correcting fluid and electrolyte imbalances through oral or intravenous (IV) rehydration while closely monitoring serum electrolytes and renal function.

Fortunately, dehydration is both preventable and treatable. Preventive measures, such as maintaining adequate fluid intake, regularly monitoring at-risk populations, and providing patient education—especially for older adults—are crucial for reducing its incidence and complications. A thorough understanding of dehydration’s causes, clinical signs, and diagnostic criteria can enhance patient care by ensuring early recognition, timely intervention, and the prevention of severe complications.