Lewis suffered from a number of chronic health problems, illnesses and addictions related both to aging and a back injury sustained in a comedic . The fall has been stated as being either from a piano while performing at the Sands Hotel and Casino on the Las Vegas Strip on March 20, 1965, or during an appearance on "The Andy Williams Show". In its aftermath, Lewis became addicted to the painkiller Percodan for thirteen years. He said he had been off the drug since 1978. In April 2002, Lewis had a Medtronic "Synergy" neurostimulator implanted in his back, which helped reduce the discomfort. He was one of the company's leading spokesmen.