A video of a breathing exercise used by author JK Rowling has been watched by millions of people around the world after being posted online by a Romford doctor.

Dr Sarfaraz Munshi, who works at Queen's Hospital, thought only his friends and family would watch.

But after JK Rowling tweeted about how it helped her recover from coronavirus symptoms millions began clicking.

The techniques works by taking five deep breaths, holding your breath for five seconds - then on the sixth breath do a big cough - covering your mouth.

Repeat twice.

Then lay flat on your front on your bed with a pillow in front of you - taking slightly deeper breaths for the next ten minutes.

The majority of your lung is on your back not on your front so by laying on your back you're closing off more of the airways - and this is not good during a period of infection.

Dr Sarfaraz Munshi

JK Rowling urged her 14 million followers to watch the video.

Author JK Rowling

Please watch this doc from Queens Hospital explain how to relieve respiratory symptoms. For last 2 weeks I've had all symptoms of C19 (tho haven't been tested) & did this on doc husband's advice. I'm fully recovered & technique helped a lot.

JK Rowling, writing on Twitter

Watch the video in full below...