UNLV Football Player Ben Christman's Cause of Death Revealed

UNLV football player Ben Christman's cause of death has been revealed ... with officials stating the 21-year-old passed away naturally.

The Clark County Office of the Coroner/Medical Examiner shared the results with TMZ Sports on Thursday ... which determined he died from cardiac arrhythmia and cardiomyopathy.

Cardiac arrhythmia is an irregular heartbeat -- either too fast or too slow -- and cardiomyopathy is a disease that impacts the heart muscle.

As we previously reported, Christman experienced chest pains during practice the day before his tragic death.

The details behind the death are heartbreaking -- a teammate returned home to check on Christman after he missed a workout ... and discovered the offensive lineman in his bedroom lying on his back, foaming at the mouth and with purple fingers.

It was determined he had been dead for "a few hours" before he was found.

Another teammate told officers about Christman's chest pains at practice on Feb. 10 ... and a coach conducted an EKG on him at the UNLV facilities. He added a cardio doctor then reviewed the tests and stated they "looked normal."

In the report, cops say Christman's room was well kept and clean ... and weapons, narcotics, medications nor any other suspicious items were not found at the scene.