Teresa Heinz Kerry, wife of US Secretary of State John Kerry, showed symptoms of "some sort of seizure", and has been admitted at a hospital in Boston, CNN reported.
Heinz Kerry, 74, became ill Sunday and was taken by ambulance to Nantucket Cottage Hospital, accompanied by her husband, Kerry's spokesman Glen Johnson said.
Once her condition became stable, she was transferred to Massachusetts General Hospital in Boston.
"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," Johnson said in a statement.
Born to a Portuguese family in Mozambique, Heinz Kerry worked for the Trusteeship Council of the UN in the 1960s when she moved to the US. Her first husband, Senator John Heinz of Pennsylvania, died in a plane crash in 1991.
Teresa Heinz married Kerry in 1995, BBC said.
