Doctors expect US secretary of state Hillary Clinton to make a full recovery from a blood clot in a vein between her brain and skull with her release from hospital planned after further treatment.
A statement released by the state department said Mrs Clinton is being treated with blood thinners at the New York-Presbyterian Hospital and will be released once a dosage has been set.
But doctors have not yet given an estimate for when she can go home and it is unclear when she will be back at work.
In the statement her doctors said: "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. In all other aspects of her recovery, the secretary is making excellent progress and we are confident she will make a full recovery."
Doctors said Mrs Clinton did not suffer a stroke or neurological damage as a result of the clot, which was found behind her right ear. They added that "she is in good spirits, engaging with her doctors, her family and her staff".
The US secretary of state, who has not been seen in public since 7 December, was revealed on Sunday evening to be under treatment for a blood clot that stemmed from a concussion she suffered in mid-December.
The concussion was itself the result of an earlier illness, described by the state department as a stomach virus she had picked up during a trip to Europe that led to dehydration and a fainting spell after she returned to the United States.
The secretary of state's health setbacks have forced her to cancel an overseas trip and postpone testimony to Congress regarding a report on the attack on the US diplomatic post in Benghazi, Libya. Her two deputies testified instead.
Mrs Clinton has said she intends to appear before Congress to discuss the attack, in which four Americans, including the US ambassador to Libya, died.
White house bid
Some have questioned Mrs Clinton's fitness to be president following her illness should she make a new run for the White House in 2016.
Barack Obama defeated her in the 2008 Democratic primary and then, upon his election as president, took the unusual step of selecting her for the most important post in his cabinet.
Mrs Clinton has played down talk of making another White House run. She is expected to step down when her replacement as secretary of state, Senator John Kerry, is confirmed by the Senate.
31 December 2012