Hamilton – who now leads rival Max Verstappen by eight points in the F1 title race – attended the podium ceremony but missed the start of the post-race press conference and visited the Mercedes team doctor.
After arriving to address the media, the Briton said: “Everything got a bit blurry on the podium.
“I’ve been fighting all year, really, with staying healthy after what happened at the end of last year.
“It’s still a battle.”
Hamilton tested positive for coronavirus in December and missed the Sakhir Grand Prix in Bahrain as Williams’ George Russell deputised for Mercedes, before returning for the season-ending race in Abu Dhabi.
“I haven’t spoken to anyone particularly about it but I think it is lingering,” Hamilton said.
“I remember when I had it, training has been different since then, the levels of fatigue that you get, it’s different.
“Who knows what it is today, maybe it’s hydration, I don’t know. But I’ve definitely not had that experience.
“I had something similar in Silverstone but it’s just way worse.”