What is it like to suffer coronavirus for weeks on end?
Some people who have developed coronavirus say they are still suffering health issues weeks later.
Now, scientists say it was vital to establish whether "post-Covid syndrome" should be recognised as an illness in its own right.
People from Sheffield, Leeds and Bradford have described symptoms lasting for weeks or even months after developing Covid-19.
Andy Tingle, 52, said: "It's not just a flu, it's not just a cold or a bug, it is a serious illness that can cause lasting effects."