A wearable article comprising a dehydration indicator adapted to measure a urine ionic strength correlated to a specific gravity of the wearer's urine and provide a visible signal when the urine ionic strength reaches a value corresponding to a predetermined threshold of the specific gravity. The wearable article may be a disposable absorbent article. The dehydration indicator may also be comprised in an insert for use with a wearable article. The dehydration indicator may provide qualitative or quantitative information about the ionic strength of the wearer's urine.