This is everything you need to know about President Trump's chronic venous insufficiency, including causes and symptoms.

White House Press Secretary Karoline Leavitt announced Thursday that President Donald Trump had been diagnosed with chronic venous insufficiency. The condition affects millions of Americans, and is not a serious health threat. However, it can be painful and disabling.

The larger veins, called deep veins, give a majority of blood to the heart while superficial veins are found under the skin surface.