 Sample size calculation: The primary aim of the proposed study is to evaluate the validity of the dehydration scale compared to the gold standard of change in weight. The hypothesis is that the correlation of the two measures will produce a correlation of at least 0.95, exceeding the 0.75 cut-off to demonstrate an excellent correlation. To detect this difference at 80 power alpha0.05, 54 subjects will be sufficient. Assuming a significant loss to follow-up at one week 40-50, a total of 100 subjects will be targeted for enrollment to ensure that 54 subjects are available to test the hypothesis of a correlation between change in score and weight at follow-up. This estimated sample size will further be sufficient to evaluate interobserver reliability and obtain a concordance correlation coefficient. 