Donald Trump has a condition common in older adults, which causes blood to pool in his veins. The US President has chronic venous insufficiency, which happens when small valves inside the veins that normally help move blood against gravity gradually lose the ability to work properly.

Chronic venous insufficiency (CVI) is a benign condition which is quite common in people aged over 70. Dr Anahita Dua, a vascular surgeon at Mass General Brigham hospitals in the US, said: “The vast majority of people have a mild to moderate form of it.”

The condition affects the legs and usually appears as varicose veins and venous ulcers.

Other symptoms include heaviness, swelling, restless legs and muscle cramps.

When blood pools in the legs as a result of CVI, it can lead to swelling. It can also result in pain and itching.

More serious cases can see people’s skin changing, ulcers, bleeding or deep vein thrombosis – blood-clotting in the leg.

Risks include having a history of blood clots, having a job where you are on your feet for a long time and being overweight.

Dr Dua said people with the condition can reduce the swelling by wearing medical-grade compression socks or stockings to help the blood circulate back to the heart. She said walking can also help.

Matthew Edwards, a doctor who chairs the Department of Vascular Surgery at Wake Forest University, told the BBC between 10 to 35% of people have CVI.

He told the broadcaster: “It can be associated with serious conditions, but in and of itself it is not a serious condition, and one that is very common.”

Upon disclosing Mr Trump’s issue, White House Press Secretary Karoline Leavitt also addressed bruising on the back of his hand during a briefing on Thursday (July 17). It was seen in recent photos covered by makeup, which wasn’t an exact match to his skin tone.

She said the bruising was “consistent” with irritation from the president’s frequent handshaking and the use of aspirin. Mr Trump, 79, takes aspirin to reduce the risk of heart attack and stroke.

Ms Leavitt said during the briefing that her disclosure of Mr Trump’s medical check up was meant to dispel recent rumours about the president’s health.

The announcement was notable given the Republican president has routinely kept basic facts about his health secret.