The three-term senator announced in 2015 that he suffers from Parkinson's disease. It was not clear whether this week's fall was related to this condition.

Isakson regularly uses a cane to walk and his mobility is limited. Despite symptoms such as a shuffling gait, a faster speech pattern and stiff left arm, the progressive neurological disease hasn't slowed him down on the job.

He chairs two Senate committees and traveled to Iraq with two colleagues this spring to visit with American service members, military leaders and government officials. He also led an official congressional delegation to Normandy to commemorate the 75th D-Day anniversary.

His openness about his health has prompted admiration from constituents, as well as occasional criticism from political opponents.

“I kind of consider it part of my job to be a role model for people who might have the disease or have a loved one who has it to say ‘things aren’t over, think positive, act positive and do positive things and you’ll be fine,’ ” Isakson told The Atlanta Journal-Constitution in 2016.

He was twice admitted to the hospital in 2017 to undergo back surgeries, the latter to address a sacral hairline stress fracture in his lower spine that was unrelated to Parkinson’s.

Georgia officials wished Isakson a speedy recovery on social media Wednesday evening.

"Johnny is a friend and a great partner in the U.S. Senate. I have no doubt he will back to work soon," colleague David Perdue tweeted.

Isakson has been in Georgia elected politics for more than 40 years. He served as the Republican minority leader in the Georgia House and was eventually elected to succeed Newt Gingrich in the U.S. House in 1999.

He has been in the U.S. Senate since 2005. He won his third term in 2016, defeating Democrat Jim Barksdale.

Isakson’s seat will be on the ballot in 2022.

Read more about Isakson here.