What is the primary cause of dry skin?

The primary cause of dry skin is insufficient moisture or hydration. When the skin does not retain enough water, it can lead to a lack of elasticity and a rough texture. Factors contributing to this condition can include environmental influences like low humidity, exposure to harsh soaps, hot showers, and certain medical conditions that affect the skin’s barrier function. Maintaining proper hydration levels in the skin is essential for overall skin health, as moisture is needed for the skin cells to function optimally and for maintaining a healthy skin barrier that protects against environmental aggressors.

Excess oil production, high levels of UV exposure, and high humidity might affect the skin's appearance and health but do not primarily cause the skin to become dry. In fact, high humidity can sometimes help maintain skin hydration. High levels of UV exposure can lead to skin damage over time, but they might not directly correlate to the immediate dryness of the skin.