Software company founder John McAfee was taken to hospital on Thursday after being denied political asylum in Guatemala.
McAfee told The Associated Press that he suffered chest pains overnight but didn't believe he had a heart attack.
A government doctor said he appeared to be suffering from high stress.
More top news
Super substitute Jill Scott marked her 101st international appearance with the winner as England squeezed past a stubborn Bosnia side
Conservative Party chairman Lord Feldman is being interviewed in an internal inquiry into bullying after the death of a young activist.
Former Davis Cup finalist John Lloyd led the tributes to Andy Murray, who ended Great Britain's 79-year wait for the famous trophy