Rep. C.W. "Bill" Young, one of the longest-serving members of Congress in history, is "gravely ill," his family said in a statement provided by Young's office.
"U.S. Rep. C. W. Bill Young's condition turned for the worse over night and he is gravely ill," the family said. "His doctors say his prognosis is guarded."
Young announced earlier this month that he will not seek reelection in 2014.
Young, 82, has served in Congress since 1971. He is the fourth-longest serving current member and his tenure ranks among the 25 all-time longest.
Young was not present for votes on Wednesday as Congress ended the government shutdown and raised the debt ceiling. The Tampa Bay Times reported he was in the hospital dealing with back problems.