Kate Major, the on-off girlfriend of Lindsay Lohan's father Michael, has reportedly suffered a seizure in rehab.

Major, who gave birth to the actress' half-sister in January, 2013, reportedly complained of chest pains on Monday (12May14), and was hospitalised at the JFK Medical Center in Florida.

Her condition is unknown.

This isn't the first medical scare for Major - in 2011, she suffered a seizure while seeking treatment at a rehab centre in Florida.