Laila Ali -- My Dad's Just Fine ... 'He's Sick But He's Alive'

Muhammad Ali is sick ... but he's alive ... so says the Champ's daughter Laila Ali.

"He's good," Laila said at LAX on Thursday ... "Rumors about [his health] every year come out."

The latest rumors were spawned from an interview Muhammad's brother gave at a screening of "I Am Ali" last week -- where he reportedly said the 72-year-old icon is in bad shape and housebound.

But Laila says there has NOT been a drastic change in her father's condition recently -- explaining, "He is sick, but he's alive."

FYI -- Muhammad was diagnosed with Parkinson's syndrome in 1984 and his health has been in a steady decline ever since.

As we previously reported, Ali hung out with boxing champ Andre Berto back in April -- and Berto told us he was alert, intelligent and rooting for Kentucky to win the NCAA tourney.