Teresa Heinz Kerry, the wife of Secretary of State John Kerry, has been upgraded from "critical" to "fair" condition following a medical emergency that required hospitalization over the weekend.
"After conducting tests overnight and this morning, doctors at Massachusetts General Hospital have upgraded Mrs. Teresa Heinz Kerry's condition from critical to fair," Kerry spokesman Glen Johnson said in a statement.
"She is undergoing further evaluation, and Secretary of State John Kerry, her son, and other family members remain with Mrs. Heinz Kerry at the hospital in Boston, as they have been since she became ill. The family is touched by the outpouring of well-wishes."
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.
The episode occurred at the couple's home on the New England island of Nantucket, where they were celebrating the July 4 holiday weekend. 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.
The secretary of State had planned to return to Washington on Monday, with the president holding a Cabinet meeting at the White House in the morning. He and Treasury Secretary Jack Lew are scheduled to host economic talks with Chinese officials Wednesday and Thursday, but it is unclear whether Kerry will still participate.
This post was updated at 4:04 p.m.