Sen. Robert Byrd (D-W.Va.), 91, has been admitted to the hospital after falling Tuesday at his home in Northern Virginia.“Byrd was taken to the hospital this morning as a precautionary measure following a fall at his home which was likely caused by standing up too quickly,— a statement from Byrd’s office said. “While having no broken bones or bruises, upon examination, doctors found an elevated white-blood cell count which can be an early sign of an infection.— “His doctors have determined that Byrd should remain in the hospital for antibiotic treatment and observation,— the statement said. Byrd, the Senate’s longest-serving Member and the president pro tem, was hospitalized in June for a minor infection. His stay was extended after he developed a staph infection. He was released on June 30 after a six-and-a-half-week stay.Senate Majority Leader Harry Reid (D-Nev.), who has not spoken to Byrd since Tuesday’s fall, told reporters, “We understand it’s nothing serious.— Byrd appeared on the Senate floor on Sept. 10 to deliver a tearful tribute to the late Sen. Edward Kennedy (D-Mass.), with whom Byrd served for close to five decades. Byrd was on the floor a week later to vote for an Obama administration judicial nominee and an amendment to the Interior and environment appropriations bill. Byrd’s office, citing a request of the family, declined to disclose the name of the hospital.