A characteristic of hyperhidrosis is excessive sweating. This condition is marked by an abnormal increase in sweating, often occurring even when the body does not need to cool down, such as in cooler temperatures or during rest. People with hyperhidrosis may experience sweat that can be so profuse that it drips off their hands, armpits, feet, or face, significantly affecting their quality of life.
In contrast, the other options pertain to opposite or unrelated conditions. Decreased perspiration is not a characteristic of hyperhidrosis, as this condition involves the opposite issue of increased sweating. Dry skin also contradicts the essence of hyperhidrosis, as the condition results in heightened moisture and perspiration. Skin discoloration does not directly connect to hyperhidrosis but may be related to other skin conditions or factors outside the realm of sweating. Therefore, excessive sweating is the defining feature that confirms hyperhidrosis.