Sen. Thad Cochran, R-Miss., announced Monday that he plans to retire from the Senate effective April 1 amid a series of health concerns after nearly 40 years in the Senate.

“I regret my health has become an ongoing challenge. I intend to fulfill my responsibilities and commitments to the people of Mississippi and the Senate through the completion of the 2018 appropriations cycle, after which I will formally retire from the U.S. Senate,” Cochran said in a statement.