Mayhew, 70, cancelled an appearance at a comic book store in Texas over the weekend after falling ill, reported TMZ.
His wife has assured fans he is expected to make a full recovery.
"He will be discharged within a few days. Doctors are incredibly happy with his improvements," she said.
The British star will portray wookie Chewbacca in J J Abrams' upcoming 'Star Wars' sequel 'The Force Awakens'.