Talking during a comic convention in 1975, Chuck Norris one of Lee’s friends and co-movie stars, explained what happened to the most famous martial arts actor of all time.
“Bruce had been lifting weights with Karim Jabaar, he hurt his back. He was laid up in hospital for three weeks. He came out feeling stronger than ever, but he needed medication to keep his back muscles loose. One day he had a headache, so (sic) gave him some antibiotics. These mixed with the medication he was on from the hospital and caused his brain to swell. That’s what really killed Bruce Lee.”
Tragic in every sense.