In August 2007, Pratchett was misdiagnosed as having had a minor stroke a few years before, which doctors believed had damaged the right side of his brain.
In December 2007, he announced that he had been newly diagnosed with early-onset Alzheimer's disease, which had been responsible for the "stroke".
He had a rare form of posterior cortical atrophy (PCA), a disease in which areas at the back of the brain begin to shrink and shrivel.

Describing the diagnosis as an "embuggerance" in a radio interview, Pratchett appealed to people to "keep things cheerful" and proclaimed that "we are taking it fairly philosophically down here and possibly with a mild optimism."
He stated he felt he had time for "at least a few more books yet", and added that while he understood the impulse to ask "is there anything I can do?",
in this case he would only entertain such offers from "very high-end experts in brain chemistry."
Discussing his diagnosis at the Bath Literature Festival in early 2008, Pratchett revealed that by then he found it too difficult to write dedications when signing books.
In his later years Pratchett wrote by dictating to his assistant, Rob Wilkins, or by using speech recognition software.

In March 2008, Pratchett announced he would donate US$1,000,000 (about £494,000) to the Alzheimer's Research Trust, and that he was shocked "to find out that funding for Alzheimer's research is just 3% of that to find cancer cures."
He said: "I am, along with many others, scrabbling to stay ahead long enough to be there when the cure comes along."

In April 2008, Pratchett worked with the BBC to make a two-part documentary series about his illness, Terry Pratchett: Living With Alzheimer's.
The first part was broadcast on BBC Two on 4 February 2009, drawing 2.6 million viewers and a 10.4% audience share.
The second, broadcast on 11 February 2009, drew 1.72 million viewers and a 6.8% audience share.
The documentary won a BAFTA award in the Factual Series category.
Pratchett also made an appearance on The One Show on 15 May 2008, talking about his condition.
He was the subject and interviewee of the 20 May 2008 edition of On the Ropes (Radio 4), discussing Alzheimer's and how it had affected his life.

On 8 June 2008, news reports indicated that Pratchett had an experience which he described as: "It is just possible that once you have got past all the gods that we have created with big beards and many human traits, just beyond all that, on the other side of physics, there just may be the ordered structure from which everything flows" and "I don't actually believe in anyone who could have put that in my head".
He went into further detail on Front Row, in which he was asked if this was a shift in his beliefs: "A shift in me in the sense I heard my father talk to me when I was in the garden one day.
But I'm absolutely certain that what I heard was my memories of my father.
An engram, or something in my head ... This is not about God, but somewhere around there is where gods come from."

On 26 November 2008, Pratchett met the Prime Minister Gordon Brown and asked for an increase in dementia research funding.
Pratchett tested a prototype device to address his condition.
The ability of the device to alter the course of the illness has been met with skepticism from Alzheimer's researchers.

In an article published mid-2009, Pratchett stated that he wished to die by assisted suicide (although he disliked that term) before his disease progressed to a critical point.
He later said he felt "it should be possible for someone stricken with a serious and ultimately fatal illness to choose to die peacefully with medical help, rather than suffer."
Pratchett was selected to give the 2010 BBC Richard Dimbleby Lecture, entitled Shaking Hands With Death, broadcast on 1 February 2010.
Pratchett introduced his lecture on the topic of assisted death, but the main text was read by his friend Tony Robinson because Pratchett's condition made it difficult for him to read.
In June 2011 Pratchett presented a one-off BBC television documentary, Terry Pratchett: Choosing t
In August 2007, Pratchett was misdiagnosed as having had a minor stroke a few years before, which doctors believed had damaged the right side of his brain. In December 2007, he announced that he had been newly diagnosed with early-onset Alzheimer's disease, which had been responsible for the "stroke". He had a rare form of posterior cortical atrophy (PCA), a disease in which areas at the back of the brain begin to shrink and shrivel.
Describing the diagnosis as an "embuggerance" in a radio interview, Pratchett appealed to people to "keep things cheerful" and proclaimed that "we are taking it fairly philosophically down here and possibly with a mild optimism." He stated he felt he had time for "at least a few more books yet", and added that while he understood the impulse to ask "is there anything I can do?", in this case he would only entertain such offers from "very high-end experts in brain chemistry." Discussing his diagnosis at the Bath Literature Festival in early 2008, Pratchett revealed that by then he found it too difficult to write dedications when signing books. In his later years Pratchett wrote by dictating to his assistant, Rob Wilkins, or by using speech recognition software.
In March 2008, Pratchett announced he would donate US$1,000,000 (about £494,000) to the Alzheimer's Research Trust, and that he was shocked "to find out that funding for Alzheimer's research is just 3% of that to find cancer cures." He said: "I am, along with many others, scrabbling to stay ahead long enough to be there when the cure comes along."
In April 2008, Pratchett worked with the BBC to make a two-part documentary series about his illness, Terry Pratchett: Living With Alzheimer's. The first part was broadcast on BBC Two on 4 February 2009, drawing 2.6 million viewers and a 10.4% audience share. The second, broadcast on 11 February 2009, drew 1.72 million viewers and a 6.8% audience share. The documentary won a BAFTA award in the Factual Series category. Pratchett also made an appearance on The One Show on 15 May 2008, talking about his condition. He was the subject and interviewee of the 20 May 2008 edition of On the Ropes (Radio 4), discussing Alzheimer's and how it had affected his life.
On 8 June 2008, news reports indicated that Pratchett had an experience which he described as: "It is just possible that once you have got past all the gods that we have created with big beards and many human traits, just beyond all that, on the other side of physics, there just may be the ordered structure from which everything flows" and "I don't actually believe in anyone who could have put that in my head". He went into further detail on Front Row, in which he was asked if this was a shift in his beliefs: "A shift in me in the sense I heard my father talk to me when I was in the garden one day. But I'm absolutely certain that what I heard was my memories of my father. An engram, or something in my head ... This is not about God, but somewhere around there is where gods come from."
On 26 November 2008, Pratchett met the Prime Minister Gordon Brown and asked for an increase in dementia research funding. Pratchett tested a prototype device to address his condition. The ability of the device to alter the course of the illness has been met with skepticism from Alzheimer's researchers.
In an article published mid-2009, Pratchett stated that he wished to die by assisted suicide (although he disliked that term) before his disease progressed to a critical point. He later said he felt "it should be possible for someone stricken with a serious and ultimately fatal illness to choose to die peacefully with medical help, rather than suffer." Pratchett was selected to give the 2010 BBC Richard Dimbleby Lecture, entitled Shaking Hands With Death, broadcast on 1 February 2010. Pratchett introduced his lecture on the topic of assisted death, but the main text was read by his friend Tony Robinson because Pratchett's condition made it difficult for him to read. In June 2011 Pratchett presented a one-off BBC television documentary, Terry Pratchett: Choosing t
Terry Pratchett