Gay rights activist David Mixner, who was admitted to a New York hospital Sunday, is in stable condition, a hospital spokeswoman confirmed on Thursday.

Officials at New York-Presbyterian Hospital at Weill Cornell would not disclose why Mixner was hospitalized, saying only that he's resting comfortably.

A blog post dated August 1, Saturday, announced Mixner had sought medical attention: “Mr. Mixner is sick and in the hospital. He will not be able to write his blog and is looking to being back and sassy in a week or so. He thanks you for your patience and kind wishes while he recovers.”

Gay rights activist and close friend Corey Johnson told gay monthly The Advocate that it was “very close over the weekend,” and that doctors had yet to diagnose Mixner's condition.

“He told me to be completely honest with you,” Johnson said. “He wants people to know he really appreciates the good wishes – they're actually helping him quite a bit.”

Mixner, who lives several hours north of Manhattan, will celebrate his sixty-third birthday in two weeks, and is best know for his public falling out with President Bill Clinton. Motivated by candidate Clinton's pledge to end gay and lesbian discrimination in the military, Mixner raised millions for Clinton's presidential bid, but the pair parted ways when President Clinton proposed “don't ask, don't tell,” the law that prohibits openly gay service in the military.

Hospital officials said there is a possibility the civil rights activist will be released next week.