One of the greatest martial artists of all time, Bruce lee experienced rapid seizures and headaches in May 1973 while doing work in a sound studio in Hong Kong and was taken to a Baptist Hospital. Doctors there diagnosed a case of cerebral edema, or swelling in the brain. No immediate causes were given.
He then experienced the same thing in July of 1973 while having dinner with the second person to portray James Bond, actor George Lazenby and one of his Chinese associates, but the episodes did not happen as qucikly as before. Bruce Lee went back to his apartment to rest, but he never woke up and was pronounced dead after he was taken by ambulance to Queen Elizabeth Hospital in Hong Kong. The doctors there also diagnosed cerebral edema. The causes were also unknown, which has led to many theories and unusual stories concerning his death.
Bruce Lee died in a Hong Kong apartment in July 1973 when he was 32 years old. He suddenly fell into a coma while taking a nap and never woke up.
Investigation carried out to ascertain the death were not absolutely certain. Authorities attributed five possible reasons for Lee's death. But all these different opinions agreed on one thing that Lees death was caused by a cerebral edema - or swelling of brain caused by a congestion of fluid. But cause of edema itself could not be established with certainty.
As per fact's available, some time after 4 P.M. on the day of his death, Lee had complained of a headache and because of that had taken a tablet of Equagesic. Around 7:30 p.m. after that he lay down for a nap at the home of Betty Tingpei, a Taiwanese actress and never woke up after that. His death was known when Tingpei tried to wake him up after sometime later.
The subsequent medical examination showed traces of cannabis in Lee's stomach, but the amount was so small that it could have been because of drinking a a cup of tea that day. The death was probably caused by hypersensitivity to one of the constituent substance in the headache tablet he took that afternoon. There were no other signs to indicate death by any reason other than edema - his skull showed no injury, none of the blood vessels were blocked or burst, no "foreign" substance other than the Equagesic was found in any part of the body.
A more detailed account of the circumstances of death of Lee and the examinations following it are availabe on the site referred below.