From tingly legs to bulging veins, these warning signs may point to chronic venous insufficiency—a widespread circulatory issue doctors say is on the rise.

A recent medical checkup of President Donald Trump revealed that mild swelling he had noticed in his lower legs was “chronic venous insufficiency,” a common medical condition among the elderly. CVI, as it’s abbreviated, is due to pooling of blood in the veins.

President Donald Trump has been diagnosed with chronic venous insufficiency, the White House announced on Thursday. Here's what to know about the condition.