Advanced Patient Assessment Practice Exam

Which disease is associated with elevations in sodium and chloride in sweat?

1. Pneumonia

2. Emphysema

3. Renal disease

4. Cystic fibrosis

The correct answer is: Cystic fibrosis

Cystic fibrosis is linked to elevated levels of sodium and chloride in sweat due to a defect in the cystic fibrosis transmembrane conductance regulator (CFTR) protein. This protein is responsible for the movement of chloride ions and, to some extent, sodium ions across epithelial cell membranes. In individuals with cystic fibrosis, the malfunctioning CFTR leads to decreased reabsorption of chloride in the sweat ducts, resulting in higher concentrations of both sodium and chloride in sweat. The condition is primarily recognized through the sweat test, which measures the salt content in a person’s sweat, and significantly elevated levels support the diagnosis of cystic fibrosis. This association is a key diagnostic criterion for the disease, making it identifiable in clinical settings. The other options listed—pneumonia, emphysema, and renal disease—do not typically present with the classic symptom of increased sodium and chloride levels in sweat, making them less relevant in this context.