Senator Bernie Sanders is off the presidential campaign trail until further notice after a procedure to clear a blocked heart artery.
The senator reportedly had discomfort in his chest last night.
He went in for tests, and then doctors opened a blocked artery and inserted two stents.
This is a fairly common problem. Doctors perform nearly one million of these procedures every year.
The arteries become blocked, usually by a buildup of cholesterol, restricting blood flow to the heart muscle.
A complete blockage can lead to a heart attack, but partial ones usually cause shortness of breath or chest pain, such as a pressure or tightness in the middle or side of your chest.
We don't know which of Sanders' heart arteries was involved - each supplies a different area of the heart muscle.
To open the vessel, a long-thin catheter is inserted into the narrowed section, followed by a wire and a balloon. The balloon is inflated to open the vessel, then a wire mesh stent goes in to keep it open.
If the artery is opened soon after the blockage develops, the prognosis is good.
"The main therapy is you take blood thinners for anywhere from about 3 months to a year, which again are very safe and very well-tolerated. And many people can get back to work and whatever they're activity may be - whether they be a politician or a businessman or a factory worker, they can get back to work fairly quickly," said Dr Steve Nissen, a cardiologist with the Cleveland Clinic
The 78-year-old Senator will also have to see his doctor for a follow-up in a few weeks, and regularly from then on.
Senator Sanders has no history of cardiovascular disease.
A 2016 letter from his doctor said he's had treatments over the years for mildly high cholesterol, an underactive thyroid gland, diverticulitis, and laryngitis from acid reflux.
He's known to be a big walker, marching in 3 parades this past 4th of July.
Bernie Sanders' heart procedure a common one