During a regular news briefing, Press Secretary Karoline Leavitt revealed that Trump, 79, had noticed swelling in his legs, prompting a check-up with his doctor who diagnosed him with the condition. Trump had also been recently photographed with patches of make-up on the back of his hand. The White House has said it is unrelated to the vein condition but is instead bruising as a result of frequent handshaking. Here are the some of the key things to know about the US president's diagnosis.

Trump's condition is "benign and common", particularly in individuals over the age of 70, according to a note from White House physician, Captain Sean Barbabella, released to reporters. Chronic venous insufficiency occurs when leg veins don't allow blood to flow back up to the heart, causing it to pool in the lower limbs. Normal blood flow from the legs back up to the heart moves against gravity, which in older people can become a difficult process. This can be due to weakening valves in veins, something that can occur as people age. (BBC)