From WENN.com

The former First Lady was taken to New York-Presbyterian Hospital, where she was given anticoagulants to prevent further blood clotting.

The clot was discovered on Sunday (30Dec12) at a medical exam following up from the 65-year-old politician's medical scare earlier this month (Dec12).

Clinton suffered concussion after fainting from dehydration, brought on by a stomach virus.

Deputy Assistant Secretary of State Philippe Reines says, ""Her doctors will continue to assess her condition, including other issues associated with her concussion. They will determine if any further action is required.""