Sen. Chris Van Hollen said in a statement released Sunday night he suffered "a small stroke."
"Earlier today, an angiogram indicated that I had experienced a minor stroke in the form of a small venous tear at the back of my head," the Maryland Democrat said in his statement.
Van Hollen said he experienced "lightheadedness and acute neck pain" as he giving a speech in the western part of his state. He then went to George Washington University Hospital.
"Fortunately," he said, "I have been informed that there are no long-term effects or damage as a result of this incident, but my doctors have advised that out of an abundance of caution I remain under observation for a few days."
Van Hollen's announcement came on the same day Pennsylvania Lt. Gov. John Fetterman, who is in the middle of a primary campaign for the U.S. Senate, said he suffered a stroke Friday.