Secretary of State Hillary Clinton has been admitted to a hospital with a blood clot following a concussion she suffered several weeks ago.

A spokesperson, Philippe Reines, said in a statement the clot was discovered during the course of a follow-up exam.

"She is being treated with anti-coagulants and is at NewYork-Presbyterian Hospital so that they can monitor the medication over the next 48 hours," Reines said.

Doctors are expected to make a determination shortly about whether any further action is required, Reines said.