Updated

Teresa Heinz Kerry's condition has been upgraded from critical to "fair," according to a spokesman, after the wife of Secretary of State John Kerry was rushed to a Massachusetts hospital over the holiday weekend.

Kerry spokesman Glen Johnson said Monday that Heinz Kerry continues to undergo further evaluation. He said the secretary of State and other members of the family are with her at Massachusetts General Hospital in Boston. Doctors upgraded her condition after conducting a series of tests.

"The family is touched by the outpouring of well-wishes," he said.

Heinz Kerry was first taken by ambulance to a Nantucket hospital on Sunday. The family has not offered additional details on her condition, though speculation has focused on symptoms potentially connected with those of a seizure.

Nantucket Police Lt. Jerry Adams said a call requesting medical aid was received just after 3:30 p.m. for a home on Hulbert Avenue, and an ambulance was dispatched. Online records show the property is connected to Heinz Kerry's family.

Heinz Kerry is the widow of former U.S. Senator John Heinz, heir to the Heinz ketchup fortune. She married John Kerry in 1995.

Doctors treated her for breast cancer in December 2009.

She previously has said she found in late September that year that she had cancer in her left breast after having her annual mammogram.

A month later, she underwent lumpectomies on both breasts at a Washington hospital after doctors also discovered what they thought was a benign growth on her right breast.

That diagnosis was initially confirmed in postoperative pathology, but two other doctors later found it to be malignant.

In November 2009, Heinz Kerry had another pair of lumpectomies performed at Massachusetts General Hospital.

John Kerry had been at the Nantucket home since returning from nearly two-week around-the-world diplomatic trip to the Mideast and Southeast Asia in the pre-dawn hours of July 3.

Before his wife's medical problem, he had planned to return to Washington on Monday and then co-host with Treasury Secretary Jack Lew high-level strategic and economic talks with senior Chinese officials on Wednesday and Thursday.

Kerry had also spoken of his desire to make his sixth trip to Israel as secretary starting at the end of the week. State Department officials said

Kerry's schedule is now influx pending developments with his wife's health.

The Associated Press contributed to this report.