WASHINGTON (AP) — Rep. John Dingell, the longest-serving current member of Congress, was admitted to a Washington-area hospital Tuesday afternoon because he was feeling ill.

The Michigan Democrat was fully conscious and went to the hospital as a precautionary measure, his office said. Dingell had been working in his Capitol Hill office when he decided to seek medical treatment.

Dingell, 82, was defeated last week by Rep. Henry Waxman, D-Calif., in a Democratic caucus vote to lead the House Energy and Commerce Committee. He had served as the committee's chairman for the past two years and had been the panel's top Democrat for 28 years.

He was expected to return to work in a day or so, said spokesman Adam Benson. The spokesman said Dingell joked with staff on his cell phone on the way to the hospital.

Dingell had surgery to replace his left knee in late October and has used crutches or a cane to move around the halls of Congress in recent years. He was first elected to Congress in 1955 and is scheduled to become the longest-serving House member in history in February.