Brian Wilson's Cause of Death Revealed

Brian Wilson had multiple respiratory issues when he passed away ... and, now we know the reason why he simply stopped breathing.

TMZ has obtained the death certificate for Wilson ... which lists "respiratory arrest" as his main cause of death. According to the American CPR Care Association, respiratory arrest occurs when the heart is still beating, but the lungs stop functioning, making it impossible for the person to get oxygen.

Sepsis and cystitis -- infection issues -- are also listed on the document ... and, associated factors include neurodegenerative disorder, obstructive sleep apnea, chronic respiratory failure and chronic kidney disease.

Basically, Brian was an older individual who wasn't in great health ... and, he died of natural causes. His family announced last year he was suffering from dementia.

Remember ... Wilson's family announced his passing earlier this month -- announcing they were heartbroken and asking for privacy during this difficult time.

Brian rose to fame as a founding member of the Beach Boys ... leading them during their formative years, before the group's well-documented issues.

Wilson's longtime wife Melinda, died in 2024, and his family filed for a conservatorship shortly after to handle Brian's affairs.

Brian was 82.