U.S. Secretary of State John Kerry's wife, Teresa Heinz Kerry, was rushed to a top Boston hospital from the island of Nantucket, Massachusetts, on Sunday, with an unspecified medical condition.
Glen Johnson, a State Department official who serves as Kerry's personal spokesman, announced her illness but did not give details.
The 74-year-old philanthropist and heiress was in critical but stable condition, a Boston newspaper reported.
"Late Sunday afternoon, Mrs. Teresa Heinz Kerry was taken by ambulance to Nantucket Cottage Hospital, accompanied by her husband," Johnson said in a brief written statement released by the State Department.
"Once doctors had stabilized her condition, she was transferred to Massachusetts General Hospital in Boston, again accompanied by the secretary," he added. "The family is grateful for the outpouring of support it has received and aware of the interest in her condition, but they ask for privacy at this time."
Massachusetts General Hospital is among the United States' top medical centers and is one of the Harvard Medical School's teaching hospitals.
Earlier, a source close to the family said Heinz Kerry's trip to the hospital from the family's summer residence in Nantucket, an island where many wealthy Americans have vacation homes, was necessitated by a "medical condition" rather than an accident.
On its website, the Boston Herald newspaper quoted Cottage Hospital spokesman Noah Brown as saying Heinz Kerry was admitted to the emergency room in critical condition. Her condition has since stabilized, the paper quoted him as saying.
Brown said he had been asked to refer questions to the State Department.
Kerry and his wife have long vacationed on Nantucket, about 30 miles (48 km) off the south coast of Cape Cod. Many wealthy Americans have summer homes there.
Heinz Kerry was born in the southern African nation of Mozambique and is the widow of Pennsylvania Senator John Heinz III, an heir to the Heinz food fortune.
Heinz, a Republican, died in a helicopter crash in 1991 and she married Kerry, then a Democratic U.S. senator from Massachusetts, in 1995 on Nantucket.
Kerry was one of the richest U.S. senators, mostly due to Heinz Kerry's fortune.
Heinz Kerry is known for being outspoken and famously told a reporter to "shove it" during her husband's unsuccessful presidential bid in 2004.
Kerry's second wife, she is the chairman of the Heinz Endowments and the Heinz Family Philanthropies.
She is active in environmental issues, has served on numerous boards and has been awarded 10 honorary degrees, according to the Heinz Endowment's website.