WASHINGTON — Secretary of State Hillary Rodham Clinton was admitted to a New York hospital Sunday after the discovery of a blood clot stemming from the concussion she sustained earlier this month.

Clinton’s doctors discovered the clot Sunday while performing a follow-up exam, her spokesman, Philippe Reines, said. He would not elaborate on the location of the clot but said Clinton is being treated with anti-coagulants and would remain at New York-Presbyterian Hospital for at least 48 hours so doctors can monitor the medication.