(WTVO) — Medical researchers believe they’ve finally found the cause of Bruce Lee’s mysterious death almost 50 years ago.

Lee, at the time 32 years old, was awaiting the release of his first major Hollywood motion picture, “Enter the Dragon,” when he died in 1973 of cerebral edema, or swelling of the brain.

Lee was known as one of the fittest people on Earth, with a low ratio of body fat to muscle, so his death took the world by surprise.

Prior to the release of “Enter the Dragon,” Lee had arranged a lunch meeting with James Bond actor George Lazenby to discuss an upcoming project. During lunch, he complained of a headache and retired to his hotel room, took a painkiller and was later found dead.

Cerebral edema was determined to be the cause. At the time, doctors believed that reaction to a painkiller may have been responsible.

Now, nearly 50 years later, as reported by Clinical Kidney Journal, researchers believe drinking excess water and prior kidney injury caused his death.

“Ironically, Lee made famous the quote ‘Be water, my friend,’ but excess water appears to have ultimately killed him,” the researchers wrote.

Doctors suggest that hyponatraemia, a low concentration of sodium in the blood, which can be caused by having too much water in the body, may have been the true cause of his death.

The researchers make the case that Lee was at risk for hyponatraemia because of his high liquid intake, marijuana usage or use of prescription drugs or alcohol, and a past history of kidney injury.

“We propose that the kidney’s inability to excrete excess water killed Bruce Lee,” the researchers wrote.

Lee’s death shocked the world, leading to rumors that he was killed by triad gangsters, a jealous lover, or was the victim of a curse.

“In conclusion, we hypothesize that Bruce Lee died from a specific form of kidney dysfunction: the inability to excrete enough water to maintain water homeostasis, which is mainly a tubular function,” researchers wrote. “This may lead to hyponatraemia, cerebral oedema and death within hours if excess water intake is not matched by water excretion in urine, which is in line with the timeline of Lee’s demise.”

Lee was survived by his wife, Linda Lee-Caldwell, daughter Shannon, and son Brandon. Brandon Lee was killed when an improperly cleaned prop gun fired a projectile into his abdomen on the set of “The Crow” in 1993.

Hyponatraemia

According to Mayo Clinic, symptoms of hyponatraemia can range from nausea/vomiting, headache, fatigue and muscle weakness. More severe symptoms include seizures and coma.

If you believe you may be experiencing hyponatraemia, it’s recommended you contact a doctor.

Those at increased risk of the condition (based on age, medications, etc.) should consult with their physician on possible preventative measures, which can include weighing water intake against water loss for balanced hydration. Additionally, doctors may recommend drinking electrolyte sports beverages like Gatorade or Powerade instead of water to refuel during high-intensity activities.