Former Arizona GOP Sen. John Kyl said Tuesday that he has been diagnosed with dementia and is retiring from public life. 

"I was blessed to represent the people of Arizona in Congress and to have numerous other opportunities to contribute to the political and civic life of our nation and state," Kyl said in a statement. "However, the time has come for me to withdraw from public life. I have been diagnosed with a neurological disease manifesting as dementia."

The 83-year-old Kyl represented Arizona in both chambers for almost 30 years. He served in the House from 1987 to 1995, then in the Senate from 1995 until 2013. When he left Congress, he was Senate minority whip, the No. 2 Republican in the chamber, according to NBC News.

Although Kyl has been retired from Congress for years, he was still active in public life, serving as an expert on the U.S. Constitution and serving as a key figure in the Central Arizona Project, ensuring water security throughout the western states, according to local FM radio station KTAR News.