Which is a common sign of dehydration in adult patients?

A common sign of dehydration in adult patients is the presence of dry mucous membranes. This occurs because when the body is dehydrated, it lacks sufficient fluid in the tissues, leading to dryness in areas such as the mouth, tongue, and other mucous membranes. This symptom is particularly noticeable as the moisture that normally keeps these tissues hydrated is depleted, making this a key indicator for healthcare providers to assess hydration status.

Increased appetite is not typically associated with dehydration; in fact, some patients may experience a reduced appetite when dehydrated. Elevated blood pressure is usually not a sign of dehydration either, as dehydration often leads to lower blood volume, which can result in decreased blood pressure. Frequent urination is contrary to what is expected during dehydration, as the body tends to retain fluids rather than expelling them when dehydrated. Therefore, dry mucous membranes are a clear and reliable sign of dehydration in adult patients.