(LOS ANGELES) -- Tennis great and pitchwoman Serena Williams was treated at Los Angeles' Cedars-Sinai Medical Center Monday for a blood clot in her lung. Her spokeswoman Nicole Chabot told People magazine that Williams "underwent emergency treatment at Cedars for a hematoma she suffered as a result of treatment for a more critical situation." Chabot's statement said Williams "suffered from a pulmonary embolism which was discovered upon her return to L.A." and that Williams "had been in New York for doctor appointments for the ongoing issues with her foot."
Williams severely cut her foot on glass in Spain last year and has undergone multiple surgeries to try to repair the injury. The athlete was seen out and about at Elton John's AIDS Foundation Academy Awards viewing party on Sunday in Los Angeles, which is why she was taken to Cedars-Sinai for treatment and observation.
On Wednesday, Williams tweeted just a two-word hint of her serious situation: "Tough day."
Copyright 2011 ABC News Radio