Current Secretary of State Hillary Clinton had to be admitted to the hospital Sunday when her doctors discovered she had a blood clot while performing an exam to follow up on her condition in relation to the concussion Clinton suffered earlier in December, said her spokesperson.

No timetable was released regarding Clinton’s release from the hospital but doctors hinted that she could be at New York’s Presbyterian Hospital at least for another 48 hours. The doctors wanted to monitor Clinton’s condition and treat the blood clot with anti-coagulants, said the U.S. Deputy Assistant Secretary of State Philippe Reines.

Reines said that Clinton’s doctors would make an assessment of her condition later on Monday, which would include other issues that deal with her recent concussion. Once the doctors have assessed her, they would make a determination if further medical treatment is needed, said Reines.

It was not released as to where the blood clot was located. Clinton, who is 65, had been suffering from a virus in her stomach earlier in December when she fainted because of dehydration, which caused her concussion.

Clinton spent time during the holidays working from her home while with her family. She had been scheduled to return to the State Department after the first of the year, after being out of work for more than three weeks.

Due to her illness, she was not able to testify before the House Foreign Affairs Committee on December 20 regarding the Benghazi, Libya U.S. Consulate attack. Bills Burns and Thomas Nides two deputies for the State Department appeared in place of Clinton.

Clinton is scheduled to step down from her post and President Obama has already nominated Senator John Kerry to replace Clinton Secretary of State.