Teresa Heinz Kerry in Fair Condition

Mrs. Kerry's condition was upgraded Monday from critical to fair.

Teresa Heinz Kerry speaking photo via

Teresa Heinz Kerry speaking photo via s_bukley/Shutterstock.com

Updated 2:55 p.m.: NBCNews.com is reporting that Teresa Heinz Kerry suffered “grand mal seizure” of unknown origin, “an electrical storm in the brain” that sent her to the hospital in critical condition Sunday, a medical source who treated her told NBC News.

She had to be intubated, the source said, which would be unusual, according to doctors who specialize in epilepsy and other seizure disorders.

A grand mal seizure, also known as a generalized tonic clonic seizure, is the most serious type, one that involves the entire body and typically causes the victim to lose consciousness.

While vacationing in Nantucket over the July 4th holiday, Teresa Heinz Kerry, wife to U.S. Secretary of State John Kerry was taken by ambulance to Nantucket Cottage Hospital and then flown to Massachusetts General Hospital after having what some early reports called a stroke. At this time, there has been no official announcement about what caused her hospitalization. Glen Johnson, personal spokesman for Secretary of State John Kerry released this statement:

Late Sunday afternoon, Mrs. Teresa Heinz Kerry was taken by ambulance to Nantucket Cottage Hospital, accompanied by her husband,” Johnson said in a prepared statement. “Once doctors had stabilized her condition, she was transferred to Massachusetts General Hospital in Boston, again accompanied by the Secretary.

Mrs. Kerry’s condition was “critical but stable” last night but has since improved, according to a new statement by Johnson:

After conducting tests overnight and this morning, doctors at Massachusetts General Hospital have upgraded Mrs. Teresa Heinz Kerry’s condition from critical to fair.

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.

Mrs. Kerry speaks five languages and is a world-renowned philanthropist  who recently helped fund a prescription drug program for low-income Mass. state residents. She is also a breast cancer survivor and mammogram advocate. She gave a rousing speech (I was there) at the 2004 Democratic National Convention held at the Garden (then the FleetCenter) where her husband received the Democratic Party’s presidential nomination. It was no easy task, either. One of her opening acts was a little known senator out of Illinois named Barack Obama.

There has been an outpouring of support on social media for the Kerry family. We will update the story when we have more information.