US Secretary of State Hillary Clinton, who had collapsed last month and suffered a concussion, is being treated with blood thinners for a clot in a vein of her brain and doctors are confident of a complete recovery.
Clinton, 65, was admitted to a New York hospital on Sunday after doctors discovered a blood clot related to the concussion she suffered last month after she fainted and fell down while recovering from a stomach infection.
"In the course of a routine follow-up MRI on Sunday, the scan revealed that a right transverse sinus venous thrombosis had formed," said Dr Lisa Bardack from Mt Kisco Medical Group, and Dr Gigi El-Bayoumi, from George Washington University, in a statement.
"This is a clot in the vein that is situated in the space between the brain and the skull behind the right ear," the doctors treating her said a day after she was admitted to the New York-Presbyterian Hospital.
Clinton is set to retire this month after being America's top diplomat for four years and President Barack Obama is replacing her with Senator John Kerry.
Her health condition restricted her to working from home for most part of the last month during which she also spent the holidays with family.
Due to her illness, she could not testify last month before the House Foreign Affairs Committee on the attack on the US embassy in Benghazi, the episode that the opposition Republicans used extensively to put her in a tight spot.
"It (the clot) did not result in a stroke, or neurological damage. To help dissolve this clot, her medical team began treating the Secretary with blood thinners. She will be released once the medication dose has been established," the doctors said.
"In all other aspects of her recovery, the Secretary is making excellent progress and we are confident she will make a full recovery," the statement said.
Doctors said Clinton, who competed with Obama for the Democratic presidential primary in 2008, was in good spirits and was engaging with her doctors, her family as well as her staff.