A person reading about a rare condition is identifiable by their interest alone. That is the reason this page states plainly what runs and what it can see, in terms a reader can check against what the site actually does, and the reason turning analytics off takes one click from the footer of every page.
What is stored on your own device
Your display choices — theme, motion, contrast, text size and link emphasis — are kept in your browser's local storage so the site does not forget them between visits. They stay on your device, are never sent to a server, and clearing your browser data removes them.
Before any of this changes
- A lawful basis for each purpose, approved by the owner
- A retention schedule, stated on this page before collection begins
- A named receiving inbox and an operational process for what arrives in it
- Security controls appropriate to what is held
- This page updated first, and the change recorded as a correction
We do not ask for them and the form says so three times, but people sometimes explain why they are writing. If that happens we answer the question you asked, we do not repeat the detail back to you, we do not copy it anywhere else, and it is deleted with the rest of the enquiry. We cannot review symptoms, test results or treatment plans, and we cannot advise on an individual.
Analytics runs from your first visit, and it uses cookies to do so. Google processes what it collects on our behalf, including outside the United Kingdom. Your search terms, your accessibility and display choices, and anything describing or inferring health are not part of it — the search index runs in your browser, display choices never leave your device, and no health detail is collected anywhere on this site. Turning analytics off stops the cookies and stops anything about your visit being sent. Your browser still loads one file from Google, because it is part of every page, and it reports nothing back.