The Harry Potter creator broke the news on Monday, sharing a "life-saving" breathing technique she credited with getting her through it, having been advised to do so by her doctor husband Neil Murray.
"Please watch this doc from Queens Hospital explain how to relieve respiratory symptoms," she tweeted. "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."
The symptoms of COVID-19 include fever, fatigue, a dry cough and difficulty breathing.
The 54-year-old didn't say why she opted not to get tested; however she did reassure concerned fans who immediately began reaching out.
Thank you for your kind and lovely messages! I really am completely recovered and wanted to share a technique that's recommended by doctors, costs nothing, has no nasty side effects but could help you/your loved ones a lot, as it did me. Stay safe, everyone x
"Thank you for your kind and lovely messages!" she followed up a couple of hours later. "I really am completely recovered and wanted to share a technique that's recommended by doctors, costs nothing, has no nasty side effects but could help you/your loved ones a lot, as it did me. Stay safe, everyone x"
In the video, the doctor advises a breathing technique for people who are displaying symptoms, adding it is even helpful to perform before one gets infected.
"What I need you to understand is that once you have an active infection, you need to be getting a good amount of air into the bases of your lungs," he says.
He directs patients to take five deep breaths in, hold for five seconds, a sixth deep breath in followed by a cough, and repeating those steps a second time. Crucially, he then advises lying flat on your front for ten minutes -- not on your back, as most hospital patients are.
"Because you've got to understand, that the majority of you lung is on you back, not on your front. So by lying on your back you are closing off more of the airways, the smaller airways. This is not good during a period of infection," he says, warning it could lead to a second bout of pneumonia.
While Rowling may have been lying on her chest during lockdown, she hasn't been sitting on her hands.
Last week she launched the Harry Potter At Home hub, a new platform to entertain Potter fans new and old alike, with articles, quizzes, puzzles and craft videos, as well as reading guides for newbies.
Rowling also used Twitter to lash out at so-called "life coaches", who are pressuring people to be productive during quarantine.
"If you're a 'life coach' who's on here implying people are losers if they aren't learning a new skill/building a brand while on lockdown, maybe stop. People have challenges you know nothing about. Sometimes getting through something is more than enough," she wrote.
"Implying that people are lazy or unmotivated if they aren't knocking out masterpieces daily isn't inspiration, it's a form of shaming. If endless distraction cured depression, no rich person or workaholic would ever have killed themselves. Sadness and anxiety aren't weaknesses, they're a natural human response to difficulty and danger."
She added: "Allowing ourselves to feel what we feel, and acknowledging that we have good reason to feel that way, is a better route back to good mental health than beating ourselves up for not being superhuman."
Almost 50,000 people have tested positive for COVID-19 in the UK, and almost 5,000 have died.