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.

Chronic Venous Insufficiency (CVI) is a long-term medical condition in which the veins in the legs are unable to efficiently return blood back to the heart. This occurs when the valves in the leg veins - which normally keep blood flowing upward - become damaged or weakened, causing blood to pool in the lower limbs.