Lauren Boebert has May-Thurner syndrome. What is it?

Republican congresswoman Lauren Boebert says she has May-Thurner Syndrome, a rarely-diagnosed condition that tends to affect women more than men.

The Colorado representative was diagnosed after going for surgery to have "an acute blood clot" removed.

She was taken to hospital after severe swelling in her upper left leg, her campaign staff said on Tuesday.

The surgery was successful and Ms Boebert is expected to make a full recovery, they added.

Medics say May-Thurner syndrome (MTS) is not necessarily dangerous in itself but can lead to complications and health risks.

It is a condition caused by a problem involving the right iliac artery, which carries blood to the right leg, and the left iliac vein, which returns blood from the left leg towards the heart.

These blood vessels naturally cross over each other in the pelvis. MTS results when the artery squeezes the vein, resulting in reduced blood flow in that vessel.

But reduced blood flow can increase the risk of blood-clot formation. If a clot travels to the heart, lungs or brain it can cause a blockage with potentially fatal consequences.

MTS often presents itself through pain or cramp in a person's arm or leg, accompanied by swelling or a discolouring of the skin. Veins can appear more pronounced.

Diagnosis may be confirmed following a CT scan, as was the case with Ms Boebert.

The short answer is that doctors do not know. But they believe it affects certain groups more than others. They also think it is more common than the number of people diagnosed would suggest.

Ms Boebert's team pointed out that "women between the ages of 20 and 45 who have given birth are also more likely to have May-Thurner syndrome".

As a 37-year-old mother of four, Ms Boebert fits that description.

Many people with MTS do not seek treatment as the condition does not present them any problems that prompt them to do so.

Options available to medics include inserting a stent, a small tube that makes sure the compressed vein stays open. This is the form of treatment that Ms Boebert's team said the congresswoman received.

Other surgery may be considered to restore typical blood flow - for example by moving artery that is compressing the vein, or by creating an entirely new route for the vein.

People with MTS experiencing blood clots may be given medication in an attempt to break those up.

Those with mild symptoms might be advised by their doctor to wear compression socks on their lower legs to improve blood flow.

Because the cause of the syndrome is unknown, there is no definite way to prevent it, according to the Cleveland Clinic.

However, it has general advice for improving blood flow and reducing the risk of clots. It recommends avoiding long periods of sitting, not smoking, exercising regularly and drinking water.

A doctor who treated Ms Boebert was quoted by the congresswoman's campaign team as saying the surgery was successful, and that she is expected to make a full recovery.

"Patients with May-Thurner syndrome who undergo the procedure to restore blood flow are able to live and work just as they have in the past after a brief recovery," the doctor added.

Ms Boebert herself thanked the staff at the UCHealth Medical Center of the Rockies "for their great care and providing helpful insight on my recent diagnosis".

She said she looked forward to continuing her campaign. She currently represents the state's 3rd congressional district, but plans to switch to the 4th district.