Chargers head coach Jim Harbaugh had to leave the sideline early in his team’s Week 6 matchup with the Broncos, but was able to return to the field later in the first quarter.

Los Angeles announced that Harbaugh was dealing with an illness, with the head coach shedding some light on what happened.

CBS sideline reporter AJ Ross reported that Harbaugh said he left the sideline due to an arrhythmia, something he has been dealing with for some time. But after returning to the locker room, he felt well enough to resume coaching the game.

The Chargers hold a 23-7 lead over the Broncos early in the fourth quarter. Quarterback Bo Nix got Denver on the board with a 2-yard touchdown pass to receiver Troy Franklin with 10:06 left in the game.