The fatal clot, called a pulmonary thrombosis, went from his legs to his lungs. The report goes on to state that Shandling had an enlarged heart at the time of his death.
The comedian -- best known for his Showtime series, It’s Garry Shandling’s Show -- also had traces of drugs in his system, including Xanax, Codeine and Hydrocodone.
According to the report, Shandling's death has been ruled an “accident” and “natural.”
On March 24, the Los Angeles Fire Department received a call at 10:40 a.m. on the street where Shandling lived in Brentwood, California. He was transported to St. John's Hospital in Santa Monica, where he was pronounced dead.
WATCH: Garry Shandling's Famous Friends Gather at His House to Play Basketball, Remember the Late Star
Shandling's death was unexpected to many of his friends and co-stars in Hollywood. "It was such a shock and you deal with it," Shandling's friend and Town and Country co-star, Goldie Hawn, told ET not long after his passing. "It's life and it happens to everybody one way or another, but when somebody passes that's special and you love, it hurts. ...We'll miss him a lot."