What is a common symptom of dehydration in patients?

Increased thirst is a common symptom of dehydration because it is the body’s way of signaling that it needs more fluids. When a person becomes dehydrated, the body's fluid levels drop, and this triggers receptors in the brain that cause a sensation of thirst. This response is crucial, as it encourages individuals to drink fluids to restore hydration levels and maintain proper bodily functions.

Weight gain would typically be associated with fluid retention or excessive caloric intake rather than dehydration. Excessive sweating can occur during dehydration, but it’s not a direct symptom; rather, it can be a cause of fluid loss. Shortness of breath isn’t directly related to dehydration but could occur in various health conditions; it doesn't serve as an indicator of fluid levels in the body. Thus, increased thirst is the most direct and notable symptom signaling dehydration.