U.S. Secretary of State Hillary Clinton was hospitalized on Sunday in New York City after suffering a blood clot, the Department of State announced.

In the course of a follow-up exam today, Clinton's doctors discovered a blood clot had formed, stemming from the concussion she suffered several weeks ago, Philippe Reines, a spokesperson for the Department of State, said in a statement today.

"She is being treated with anti-coagulants and is at New York Presbyterian Hospital so that they can monitor the medication over the next 48 hours," the Department announced.

Her doctors will continue to assess her condition, including other issues associated with her concussion, the Department said. They will determine if any further action is required.

Her admittance to the hospital comes amid worries about the health of the key member of President Barack Obama's cabinet.

Clinton, 65, canceled a trip to North Africa and the Middle East on December 15 after she suffered a stomach virus. She reportedly fainted due to dehydration and suffered a concussion.

She also canceled testimony before Congress on December 20 about the September 11 attack in Benghazi, Lybia that killed U.S. Ambassador to Lybia Chris Stevens and three other Americans.

Some conservative commentators have suggested that she was faking her illness to avoid testifying but U.S. officials have denied that claim.

Officials have described her condition as improving and according to Reuters, they have dismissed reports that her illness is more serious.

Clinton will step down as Secretary of State in late January, around the time of Obama's inauguration for his second term.