What is the most common cause of secondary hypertension?

Chronic kidney disease is recognized as the most common cause of secondary hypertension due to its direct impact on the body's ability to regulate blood pressure. In this condition, the kidneys become impaired in their function, leading to a buildup of fluids and an increase in blood volume, which directly raises blood pressure. Additionally, kidney disease can disrupt the renin-angiotensin-aldosterone system, a key regulator of blood pressure, further contributing to the development of hypertension.

Other factors that could lead to secondary hypertension, such as obesity, high salt intake, and stress, often contribute to primary hypertension, which is more prevalent. While they can exacerbate existing hypertension or pose risks for developing it, they do not typically serve as the primary underlying medical condition that directly causes hypertension in the same way chronic kidney disease does.