As U.S. Sen. Mark Kirk recovers from a stroke, it'll be his decision alone on how he wants to proceed with his Senate career.
Doctors say Kirk's recovery could take weeks or months. His term ends in 2016.
Other elected officials have had to grapple with similar issues involving health and public office. Rep. Gabrielle Giffords of Arizona, for example, remained a member of Congress while performing few official duties for more than a year as she recovered from injuries suffered in an assassination attempt. She announced Sunday she plans to step down.
On the other hand, Sen. Tim Johnson of South Dakota suffered a high-profile stroke in 2006, returned to active work in the Senate the next year and remains a member today.
"It's a personal decision," said former Illinois State Board of Elections director Ron Michaelson. "It's kind of a sensitive issue, obviously."
If Kirk ever vacated the seat, it would be up to the governor, now Pat Quinn, to appoint a temporary successor until a special election could be held -- likely no later than the next scheduled congressional election.
That would give Quinn, a Democrat, the power to appoint someone of his own party to replace the Republican Kirk.
Such high-profile appointments can be controversial, famously so when former Gov. Rod Blagojevich appointed Roland Burris to take President Barack Obama's U.S. Senate seat a few years ago.
That's the Senate seat that Kirk now holds.