Sen. Mark Kirk, R-Ill., underwent surgery on Monday morning after suffering a stroke.

According to a statement released by his spokesperson, Kirk, 52, checked himself into Lake Forest Hospital on Saturday, where doctors found a carotid artery dissection in the right side of his neck.

“He was transferred to Northwestern Memorial Hospital in Chicago, where further tests revealed that he had suffered an ischemic stroke. Early this morning the Senator underwent surgery to relieve swelling around his brain stemming from the stroke,” the release said.

The statement called the surgery “successful,” and said doctors are very confident in Kirk’s recovery, attributing it “to his young age, good health and the nature of the stroke.”

Kirk previously served five terms in the House of Representatives and is currently serving his first term in the Senate, filling the spot originally vacated by President Barack Obama.