The Nutty Professor star was rushed to a New York City medical centre on Tuesday when he began suffering from low blood sugar just prior to a Friar's Club event honouring Tom Cruise.
Lewis was initially believed to have been released hours after his fall, but his representative has now confirmed that the star is still being treated by doctors.
"[Jerry] was kept overnight as a precaution. He gets wrapped up and engrossed in his work, and he forgets to eat. He is diabetic, and it's important for him to keep those [blood sugar] levels up," Page Six quoted Lewis's spokesperson as saying.
The star's representative continued: "[Jerry] was feeling dizzy, and since he was not in Las Vegas where his doctors are, they did take him to the hospital as a precautionary measure. He is feeling great and is anxious to get back up and back to work."
Lewis is now expected to be sent home from the hospital later today (June 14).
This latest incident is Lewis's second health scare in the last year. He was previously hospitalised for exhaustion in June 2011, but was back to performing within days.