Celebrity website TMZ says the 34-year-old rapper, who has epilepsy, suffered a number of fits and had another one after arriving at A&E.
The rap star, whose real name is Dwayne Michael Carter Jr, was treated a year ago after suffering two minor seizures.
Worried fans have been tweeting #prayforweezy after his latest seizures were reported.
Prayers up for @LilTunechi 🙏🏼 stay strong goat 😪
— Alexander (@FonzyyyMares) September 4, 2017
Lil wayne better pull through we need the carter V in our lives!!!! #PrayForWeezy
— Cee (@ohlookitschris4) September 4, 2017