Mitch McConnell, the Kentucky Republican, will miss the chamber’s votes after sustaining a fall, his office confirmed on Tuesday, injecting a fresh note of uncertainty into an already delicate legislative calendar.

The absence marks the latest health incident for the 83-year-old lawmaker, who has faced a series of public episodes in recent years that have drawn scrutiny to his physical condition and, by extension, the leadership pipeline within the Republican conference. His office did not specify the severity of the fall or where it occurred, offering only that he was under evaluation and expected to recover.

McConnell’s vote, or lack thereof, carries particular weight this week as Senate Republicans navigate a narrow majority and a packed agenda. With Democrats holding the chamber’s other 50 seats and Vice President Kamala Harris providing the tie breaking vote, every absence on the Republican side can stall or scramble leadership’s plans for advancing nominations and legislative priorities.

The Kentucky senator’s health has been a quiet but persistent undercurrent in Washington since he froze mid sentence at a July 2023 press conference, an episode his doctor later attributed to dehydration and a concussion he suffered earlier that year after a fall at a Washington hotel. That earlier incident sidelined him for several weeks and required rehabilitation.

His decision to step down from his role as Republican leader in November 2023, after nearly two decades atop the conference, was seen by many as an acknowledgment of those mounting physical challenges. He remains in the Senate, however, and his voting record has remained steady, making this week’s absence a notable departure from routine.

Senator John Thune of South Dakota, who succeeded McConnell as majority leader, was not expected to comment directly on his predecessor’s condition, but aides indicated the leadership office was prepared to operate without McConnell’s vote. The conference has not publicly discussed contingency plans for a longer term absence.

McConnell’s office said he looked forward to returning to the Capitol later this week, though they did not specify a date. For a chamber that prizes institutional continuity, the sight of an empty chair belonging to one of its most enduring figures served as a reminder of the fragility that underlies even the most powerful careers in American politics.