Former Sen. Jacob K. Javits of New York, long ailing from a degenerative muscle disorder known as Lou Gehrig's disease, developed severe breathing problems and was rushed to New York Hospital on Sunday.
He was reported in fair and stable condition with a possible lung infection.
Javits, 80, was admitted to the intensive-care ward "acutely ill with pulmonary complications," Jed Golden, a hospital spokesman, said.
Doctors later determined that Javits probably has a lung infection. He was being treated with an intravenous antibiotic to improve his breathing.