"The Senator fell this morning and sustained a minor cut to the back of his head. He did not lose consciousness but was taken to the Bethesda Naval Hospital as a precaution and will be released later today," Inouye spokesman Peter Boylan said in a statement. "The U.S. Army Captain and World War II combat veteran wanted to put a bandage on and come to work but his family insisted he get it checked out. He is fine."

Inouye, 88, is the second oldest senator in the chamber, behind only Sen. Frank Lautenberg (D-N.J.). Inouye is also the chairman of the the powerful Senate Committee on Appropriations.

—This story was updated at 1:48 p.m.