NBC News reported earlier this week that Heinz Kerry had suffered a grand mal seizure and required intubation, presumably to aid with breathing.
Grand mal seizures are considered the most serious type of seizure and typically involve the entire body and lead to loss of consciousness. They can be particularly difficult to diagnose, especially in isolation, and can be prompted by everything from a stroke to sleep deprivation.
Heinz Kerry was first admitted to a hospital on Nantucket and then airlifted to a hospital in Boston.
The widow of former Sen. John Heinz (R-Pa.), Heinz Kerry was treated for breast cancer in 2009.