Doctors discuss how common the condition is, why it happens — and whether Trump's symptoms align with his diagnosis.

Chronic venous insufficiency, or CVI, happens when veins in the legs can’t properly carry blood back to the heart. That can lead to blood pooling in the lower legs.

On July 17, the White House announced that President Donald Trump was diagnosed with a condition called chronic venous insufficiency after he noticed swelling in his legs.According to Press Secretary Karoline Leavitt,