A spokesman for Dick Van Dyke says the actor is undergoing tests for "cranial throbbing" that's causing him to lose sleep.
Spokesman Bob Palmer said Thursday the 87-year-old has been experiencing a throbbing sensation in his head when lying down. Palmer said scans and other tests have yet to yield a diagnosis.
He says Van Dyke has a strong constitution and is otherwise OK, but the "fatigue factor has become acute."
Palmer says that until Van Dyke receives a diagnosis and treatment plan, he's been advised not to fly and is resting at his Malibu home.
Van Dyke's credits include "The Dick Van Dyke Show" and "Diagnosis Murder."
He was to accept an award next week from New York's 92nd Street Y but canceled the trip.