U.S. Secretary of State Hillary Clinton delivers remarks at the...

U.S. Secretary of State Hillary Clinton delivers remarks at the opening plenary of the 19th International AIDS Conference in Washington, D.C. (July 23, 2012) Credit: Getty Images

Secretary of State Hillary Rodham Clinton was admitted to a NewYork-Presbyterian Hospital facility in Manhattan Sunday night for a blood clot stemming from the concussion she sustained earlier this month, State Department officials said.

Doctors discovered the blood clot during a follow-up exam and Clinton, 65, will remain at the hospital for two days while being treated with anticoagulants, a blood thinner, the department said.

Her condition wasn't immediately available Sunday night.

Doctors will continue to assess her condition, including other issues associated with her concussion, and will determine if any further action is required, State Department officials said.

Clinton has experienced a blood clot before. She was treated in 1998 for a large blood clot behind her right knee.

In mid-December, Clinton fell and suffered a concussion while at home alone as she was recovering from a stomach virus that left her severely dehydrated. The concussion was diagnosed Dec. 13, forcing her to cancel a trip to North Africa and the Middle East that had been planned for the next week.

The new clot was discovered during a follow-up examination Sunday. The clot's location was not disclosed.

If the clot is located in one of Clinton's legs, which is a common place for clots to begin, blood thinner medication can help dissolve the clot and prevent it from traveling to her lungs, said Dr. David Langer, a neurosurgeon at North Shore University Hospital Cushing Neuroscience Institute in Manhasset.

If the clot were to travel to her lungs, it could be life threatening, Langer said.

A clot or clots in the lungs, commonly known as a pulmonary embolism, are often small but if large enough, can stop blood flow to the lungs. Common symptoms of a pulmonary embolism, include sudden shortness of breath and a sharp chest pain that is made worse by coughing or taking a deep breath, according to the website for the Mayo Clinic.

Clinton also canceled Dec. 20 testimony before Congress about a scathing report into the Sept. 11 attack on the U.S. diplomatic mission in Benghazi, Libya, that killed Ambassador J. Christopher Stevens and three other Americans.

Some conservative commentators suggested Clinton was faking the seriousness of her illness and concussion to avoid testifying, although State Department officials vehemently denied that was the case.

Lawmakers at the hearings -- including John Kerry (D-Mass.), the Senate Foreign Relations Committee chairman nominated by President Barack Obama to succeed Clinton -- offered her their best wishes.

The former first lady and senator, who had planned to step down in January as the nation's top diplomat, is known for her grueling travel schedule.

With Bloomberg News and AP

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