Serena Williams self-diagnosed a life-threatening emergency after giving birth

There is only one kind of Serena Williams story: Serena Williams kicking ass at life. Not only does she have 23 Grand Slam titles and a beautiful baby daughter, but — as revealed in a new profile at Vogue — she self-diagnosed the life-threatening complications she faced after giving birth.

In Williams’ retelling, the day after Alexis Olympia Ohanion, Jr. was born by emergency C-section, the tennis star suddenly felt out of breath.

Because of her history of blood clots, and because she was off her daily anticoagulant regimen due to the recent surgery, she immediately assumed she was having another pulmonary embolism. (Serena lives in fear of blood clots.) She walked out of the hospital room so her mother wouldn’t worry and told the nearest nurse, between gasps, that she needed a CT scan with contrast and IV heparin (a blood thinner) right away. The nurse thought her pain medicine might be making her confused. But Serena insisted, and soon enough a doctor was performing an ultrasound of her legs. “I was like, a Doppler? I told you, I need a CT scan and a heparin drip,” she remembers telling the team. The ultrasound revealed nothing, so they sent her for the CT, and sure enough, several small blood clots had settled in her lungs. Minutes later she was on the drip. “I was like, listen to Dr. Williams!”

This story somehow grows Williams’ legend while encapsulating what we already assume about her: A deep understanding of her own body’s capabilities and limitations, calmness under pressure, and unparalleled confidence.

That anecdote, by the way, was only the beginning of six days of medical emergencies that featured additional surgeries, a hematoma in her abdomen, and a filter inserted into “a major vein” to prevent more clots from getting into her lungs. Williams spent the first six weeks of motherhood unable to leave her bed.

“No one talks about the low moments — the pressure you feel, the incredible letdown every time you hear the baby cry,” she told Vogue. “I’ve broken down I don’t know how many times.”

Despite this, Williams plans to win at least two more Grand Slam titles, which would allow her to surpass Margaret Court’s record of 24. The title of “greatest of all time,” however, has already been decided.