This is the first public acknowledgement that the congressman has been gone from his office for the last two weeks.
A statement from Jackson offers no details and asks that the privacy of his family be respected.
On campaign signs his look is determined, but Jackson's political future is a bit less certain Monday night, especially considering colleagues who saw him within a day or two of his claims of exhaustion said they saw no trouble.
Representative Jackson seems to have been vibrant, joking, laughing, singing doo waps, very normal in terms of my observations and in terms of what I saw," said U.S. Rep. Danny Davis.
The formerly camera-loving politician has been almost out of sight since allegation first surfaced in 2008 that his emissaries may have tried to buy him Barack Obama's former Senate seat.
One of them was charged in an unrelated federal case last week.
The House Ethics committee is investigating whether Jackson knew about the Senate seat sale. He denies it.
Last month, Robert Blagojevich told ABC 7's Cheryl Burton how he said it happened.
"I was approached by two individuals," Blagojevich said. "One offering $1.5 million, the other one offering $6 million dollars."
Nine days into Jackson's secret leave of absence, his Twitter feed declared: "House GOP is running out the clock when we should be working around-the-clock to create jobs & strengthen the economy."
"Exhaustion is one of those excuses politicians and other public figures use when they don't want to tell you the entire truth about what's going on," said ABC7 political analyst Laura Washington.
"You have a responsibility to your constituents and to the government to make that known, especially if it's going to be longer than a couple of days," said Rep. Brian Woodworth.
Despite the Senate seat scandal, an admission of adultery and little progress on a proposed third airport, Jackson earned 71 percent of the vote in the primary.
"I think he tries his best to represent us," said neighbor Roberta Wood.
"That's politics," said Jackson constituent LaJuana Greer. "They all have a scandal hidden somewhere in the closet."
A spokesman for Congressman Jackson refused to explain why they waited two weeks to go public with his leave of absence.
There's no word on where or how Jackson is being treated for the exhaustion, let alone when he may resume his work in Washington.