Wife of John Kerry upgraded to fair condition

The wife of Secretary of State John Kerry was upgraded to fair condition at a Boston hospital Monday after being stricken by an unknown medical condition.

Teresa Heinz Kerry, 74, was transferred to Massachusetts General Hospital on Sunday afternoon in critical but stable condition from Nantucket Cottage Hospital, where she was taken by ambulance earlier Sunday, ABC News reported.

Heinz Kerry had been vacationing with her husband in Nantucket, Massachusetts, this weekend.

"Late Sunday afternoon, Mrs. Teresa Heinz Kerry was taken by ambulance to Nantucket Cottage Hospital, accompanied by her husband, Secretary of State John Kerry," Kerry spokesman Glen Johnson told ABC News. "Once doctors had stabilized her condition, she was transferred to Massachusetts General Hospital in Boston, again accompanied by the Secretary."

The widow of former Sen. John Heinz III, Heinz Kerry survived breast cancer after being diagnosed in 2009 and has publicly encouraged other women to get regular mammograms to help with early detection of the disease.

She is the heir to the Heinz ketchup fortune, marrying Kerry in 1995.