Ages and Stages

Older adult patients are particularly at risk for altered electrolyte levels for two main reasons. First, they have a lower ratio of lean body weight to total body weight, which places them at risk for water deficit. Second, their thirst response is diminished and their renal function decreased, which makes maintaining electrolyte balance more difficult. Age-related renal changes include changes in renal blood flow and glomerular filtration rate.

Medications can also alter electrolyte levels by affecting the absorption of phosphate. Make sure to ask older adult patients if they are using over-the-counter medications such as antacids, laxatives, herbs, and teas.