At around the age of 7, Mortimer accidentally burnt down his family's home with a stray firework. He suffers from rheumatoid arthritis, which gives him great pain when he is stressed, especially before making a television series or embarking on a tour. On those occasions, he controls the illness with steroids. In October 2015, it was revealed that he was recovering from a triple bypass surgery which led to the cancellation of the first leg of the Reeves and Mortimer 25 years tour.