LONDON , England ( CNN ) -- Fantasy author Terry Pratchett has admitted that he has been diagnosed with a rare form of Alzheimer 's disease -- but says he plans to continue writing his multi-million selling Discworld books . Terry Pratchett , whose books have sold more than 45 million copies worldwide in 33 languages . Pratchett , 59 -- whose books have , according to his Web site , sold more than 45 million copies worldwide in 33 languages -- suffered what he called a `` phantom stroke '' earlier this year . In a statement titled `` an embuggerance '' on the Web site of Discworld illustrator Paul Kidby , Pratchett says that he has been diagnosed with what he terms `` a very rare form of early onset Alzheimer 's . '' `` I would have liked to keep this one quiet for a little while , but because of upcoming conventions and of course the need to keep my publishers informed , it seems to me unfair to withhold the news , '' says Pratchett , who has a strong following among fans of fantasy fiction . `` All other things being equal , I expect to meet most current and , as far as possible , future commitments but will discuss things with the various organisers , '' he continues . `` Frankly , I would prefer it if people kept things cheerful , because I think there 's time for at least a few more books yet . '' Pratchett adds that work is continuing on his next book `` Nation '' and that the `` basic notes are already being laid down for Unseen Academicals . '' In a P.S . he adds that `` I would just like to draw attention to everyone reading the above that this should be interpreted as ' I am not dead ' . I will , of course , be dead at some future point , as will everybody else . `` I know it 's a very human thing to say 'Is there anything I can do ' , but in this case I would only entertain offers from very high-end experts in brain chemistry . '' Pratchett 's Discworld novels , of which 36 have been published to date , are set in a fantasy universe through which the author satirizes modern-day life . He says in a statement on his own Web site that the series `` started out as a parody of all the fantasy that was around in the big boom of the early '80s , then turned into a satire on just about everything , and even I do n't know what it is now . '' Pratchett , who began writing while a provincial newspaper journalist in the 1960s , received the Order of the British Empire `` for services to literature '' from the Prince of Wales in 1998 . E-mail to a friend .
Multi - million selling writer has ` ` a very rare case of early onset ' 's '' . Pratchett says he continues on books , plans to honor commitments . His novels are set in a fantasy universe but depict modern day life . Received the Order of the British Empire from the Prince of Wales in 1998 .