A new theory has been proposed for the medical reasons for Jesus' death:
An Israeli researcher has challenged the popular belief that Jesus died of blood loss on the cross, saying he probably succumbed to a sometimes fatal disorder now associated with long-haul air travel.
Professor Benjamin Brenner wrote in The Journal of Thrombosis and Haemostasis that Jesus’ death, traditionally believed to have occurred 3 to 6 hours after crucifixion began, was probably caused by a blood clot that reached his lungs.
Such pulmonary embolisms, leading to sudden death, can stem from immobilization, multiple trauma and dehydration, said Brenner, a researcher at Rambam Medical Center in Haifa.
“This fits well with Jesus’ condition and actually was in all likelihood the major cause of death by crucifixion,” he wrote in the article, based on religious and medical texts.
Of course, with so much trauma involved it's impossible to speak to the issue conclusively. All we can safely say is that what killed Jesus was crucifixion. More importantly, what killed Jesus was my sins.