Which of the following is a common symptom of dehydration?

Dry mouth is a common symptom of dehydration as it occurs when the body lacks adequate fluids to maintain normal moisture levels. When the body is dehydrated, saliva production decreases, leading to a parched or dry sensation in the mouth. This symptom can often serve as an early warning sign of fluid deficiency.

In contrast, while fever, coughing, and headache can be associated with a variety of health issues, they are not specific indicators of dehydration. Fever may indicate an infection or illness, coughing might suggest a respiratory issue, and headache can arise from a myriad of causes, but these symptoms do not directly point to a lack of adequate hydration in the body. Recognizing dry mouth can help individuals identify dehydration early and take steps to replenish fluids, thereby preventing more severe health complications.