US President Joe Biden and former President Donald Trump have traded barbs in their first televised debate ahead of November's presidential election.
The 90-minute "CNN Presidential Debate" was aired live on Thursday night. It was held in Atlanta with no studio audience.
Biden's voice was hoarse from the start and he appeared to struggle at times to find his words.
Sources close to the Biden camp say the incumbent president has a cold.
Biden is now 81 years old. Trump is 78.
Polls have shown voters are concerned about the health of both candidates.
The two discussed issues such as employment. But the debate sometimes veered far from political issues, even touching on golf.
US political website "The Hill" says Democrats are now "in full panic mode" after what it called "Biden's stumbling performance."
Some US media have examined Trump's statements in the debate. They say a significant number of his claims were not backed by facts.
A CNN poll showed 67 percent of viewers thought Trump turned in a better performance.