The British actor fell ill last month (Sep13) and spent a week passing out, shedding weight, and feeling "terrible", so his wife Kristina took him to an emergency room at a hospital near their home in Monaco.
After a series of tests, he was told he has diabetes and has unknowingly suffered from the condition for some time.
Moore tells U.K. Tv show This Morning, "I have got the dreaded Tom Hanks. Tom Hanks came out with the fact he has diabetes, and about four or five weeks ago I was falling asleep and just feeling terrible and dying of thirst and literally passing out.
"My wife took me into emergency at Princess Grace Hospital in Monaco and I was straight on a slab... and I have diabetes. And I've obviously had it for quite a long time... During that week where I was falling asleep, my wife said I was losing a kilo a day. So I have had to have all my trousers taken in."