Bosh's agent, Henry Thomas, told ESPN in a text that early results are inconclusive regarding Bosh's medical condition and that they are still "sorting through everything."
Heat coach Erik Spoelstra said that Bosh is being treated at South Miami Hospital. The Heat said there would be no update Friday night before they returned to Miami.
"It's too early for an ultimate diagnosis," Spoelstra said earlier in the day, although he said he is confident the condition is not life-threatening. "I know there is a lot of speculation, a lot of rumors right now."
The Miami Herald first reported on Friday that Bosh, 30, could miss the remainder of the season if he was found to have blood clots in his lung.
The medication required to treat such a condition typically requires at least six months of limited physical activity.
Blood clots are always a serious condition, but this is a particularly scary moment for Bosh and the NBA after former Portland Trail Blazers star Jerome Kersey died suddenly Wednesday of a blood clot in his lung. Kersey was 52.
Bosh was admitted to the hospital on Thursday after complaining about discomfort in his chest for several days.
Bosh spent the early part of this week on vacation with family and friends, including teammateDwyane Wade, in Haiti.Wade said Bosh wasn't "feeling his best" on the vacation.When Bosh hadn't improved by Wednesday, hewas sent to a team doctor, and from there went to the hospital for tests.
"There just came a point in the vacation where he didn't feel right," Wade said. "He kind of relaxed and rested, and then when he got back, he did what he should have done ... [he] got to the doctor and tried to see what's up."
Wade said he spoke to Bosh on Thursday, but "no one had answers, he didn't have answers."
"They're exhausting all possibilities," Wade said.
Bosh's former teammateLeBron Jamescommented on the situation to reporters Friday.
"I texted Chris last night and, obviously, he probably doesn't have his phone, so I'm just waiting to hear back from him," he said. "I'm praying. My prayers is up. My hands is open and I'm wishing him the best. My fingers is crossed, for sure. Basketball is a small thing when it comes to health and people's family. He's so connected to me that I feel it, for sure. So every minute I'm checking to see if he's OK."
Bosh's wife tweeted an update on Friday.
Spoelstra had said at Thursday afternoon's practice that Bosh was "under the weather" but offered no specifics at that time.
Miami plays at New York on Friday night. Bosh did not fly with the team Thursday.
Bosh is averaging 21.1 points and 7.0 rebounds this season.
Information from ESPN.com's Ian Begley, Dave McMenamin and Michael Wallace and The Associated Press was used in this report.
Chris Bosh Could Miss Season With Blood Clots
Brian Windhorst on the reports that Chris Bosh's season is in jeopardy after reports that he has blood clots in his lungs.
Wade On Bosh Possibly Being Out For Season
Dwyane Wade talks about what he's heard from Chris Bosh about his condition.