Serena Williams is back home recuperating after two health scares she describes as "extremely hard, scary, and disappointing."
Her agents confirmed Wednesday that Williams suffered from blood clots in her lungs last week and later needed treatment for a hematoma.
"I know I will be OK, but am praying and hoping this will all be behind me soon," Williams said in a statement. "While I can't make any promises now on my return, I hope to be back by early summer. That said, my main goal is to make sure I get there safely."
Spokeswoman Nicole Chabot told People magazine that Williams underwent "emergency treatment" Monday for a hematoma suffered as a result of treatment for "a more critical situation," a pulmonary embolism.
The 29-year-old Williams was treated at a Los Angeles hospital.
"Thankfully everything was caught in time," her agents said in a statement. "With continued doctor visits to monitor her situation, she is recuperating at home under strict medical supervision."
Williams' mother, Oracene Price, tweeted: "Thank you for your concern. She is fine."
The winner of 13 Grand Slam titles, Williams attended Sunday night's Elton John AIDS Foundation Academy Awards Viewing Party.
On Tuesday night, Williams posted on her Twitter account, "Tough day." A few minutes later, she retweeted Kim Kardashian.
"Thank you everyone for all of your prayers, concerns, and support," Williams said in her statement. "This has been extremely hard, scary, and disappointing. I am doing better. I'm at home now and working with my doctors to keep everything under control."
The younger sister of seven-time major champion Venus Williams hasn't played an official match since winning Wimbledon for the fourth time July 3. She cut her right foot on broken glass at a restaurant shortly after the victory, and her comeback has been repeatedly delayed by complications with the injury since.
Williams had surgery after initially hurting her foot and pulled out of the U.S. Open. She resumed practising in September, but kept pushing back her return and needed an additional operation in October.
Williams missed the Australian Open in January, where she was the two-time defending champion.
Chabot told the magazine the embolism was discovered after Williams returned to Los Angeles from New York "for doctor appointments for the ongoing issues with her foot."
Dr. Mark Adelman, chief of vascular surgery at NYU Langone Medical Center, said a patient with a pulmonary embolism would need to take an anticoagulant for 6-12 months but could play sports on the medication.
"A blood clot can occur in any vein or extremity, most commonly in the leg, and can travel to the lung," Dr. Adelman wrote in an email. "Prior surgery, air travel, prolonged sitting, birth control pills, obesity and pregnancy can predispose a patient to a blood clot in the leg that can travel to the lung."
Adelman said if a clot-dissolving agent is used to treat an embolism, it can result in bleeding around the catheter used to deliver the drug. Williams' agents said the hematoma was removed.
Second-ranked Kim Clijsters tweeted Wednesday: "Just read about Serena!!!! Very scary, hope she is ok!fingers crossed!"
Williams has a wide range of business, fashion and charitable interests that keep her in the public eye even when she's not on the court. Since winning her first Grand Slam title in 1999, she has struggled with injuries on several occasions only to come back to win more championships.