NEW YORK CITY: Top US diplomat Hillary Clinton is suffering from a rare blood clot in a vein in her head but should make a full recovery, doctors said on Monday as she spent New Year’s Eve in hospital.

A routine follow-up scan on Sunday revealed “that a right transverse sinus venous thrombosis had formed,” Doctors Lisa Bardack of Mount Kisco Medical Group and Gigi El-Bayoumi, of George Washington University, said.

They described it as “a clot in the vein that is situated in the space between the brain and the skull behind the right ear.”

But they were also quick to offer reassurances saying in their statement that “it did not result in a stroke, or neurological damage.”

Clinton was admitted to the New York Presbyterian Hospital on Sunday following the discovery and is being treated with blood thinners to dissolve the clot. 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. She is in good spirits, engaging with her doctors, her family, and her staff,” they added.

The globe-trotting diplomat has not been seen in public after succumbing to a stomach virus on returning from a trip to Europe on December 7, which forced her to cancel a planned visit to North Africa.

It’s a rare absence for the most popular member of President Ba-rack Obama’s cabinet, who has been a highly visible and loyal supporter of his foreign policy agenda, traveling almost a million miles in her four years in office.

A Gallup poll released on Monday showed that Clinton again topped an annual list of the Woman Most Admired by Americans, winning support from 21 percent of those surveyed. It is the 17th time she has topped the list, a landmark for Gallup.

But Clinton, 65, has made it clear that  she intends to step down in the coming weeks, once Senator John Kerry, tapped by President Barack Obama to replace her, is confirmed by the Senate.

Dr. Neeraj Badjatia, chief of neurological critical care at the R. Adams Cowley Shock and Trauma Center at the University of Maryland Medical Center, told Agence France-Presse a clot in the head was “not common,” stressing, however, that he was not involved in Clinton’s treatment.

While Clinton’s doctors have said that she has not suffered any stroke or neurological damage, Badjatia said “because it is a type of blockage of a blood vessel in the brain, it is what we consider a type of stroke, and one of the rarest types of stroke we have.”

“It’s a very unusual form, and . . . it’s an unusual complication of a mild head injury,” he explained, adding it was hard to estimate the incidence of such clots as “it’s found when you are looking for it . . . many times it’s diagnosed by happenstance.”