John Travolta's Health Causes Concern Among His Friends John Travolta

Friends of Hollywood actor John Travolta are concerned over the health of the reclusive star.

The star of the legendary "Saturday Night Fever" has been taking midnight drives in a golf cart alone across his Jumbolair estate in Florida. He is said to be unable to sleep because he is grief stricken at the loss of his teenage son, Jett, six months ago, reported contactmusic.com.

"We often see John driving himself around at night. It's sad to see. You rarely catch sight of him during the day. We used to see him driving around on a buggy with his son. Now it's just John by himself," said a friend of the actor.

Jett died after suffering a seizure while on a family holiday in the Bahamas in January.