Irv Gotti passed away after suffering a "massive hemorrhagic stroke," and his health issues were compounded by never going to the doctor ... so says his brother.

Chris Lorenzo -- Gotti's older brother -- stopped by the "2way" podcast to talk about his little bro ... and, he revealed Irv was eating Chinese food and playing poker with friends one night when he suffered the medical emergency.

According to the National Institute of Health, a hemorrhagic stroke is one which occurs when a blood vessel in the brain bursts causing bleeding.

Lorenzo says Irv had a series of health issues because he almost never went to the doctor ... admitting that when he finally did go to get a physical, he didn't believe it when the doctors told him he was diabetic.

As we told you ... Irv passed away earlier this month -- about six months after he suffered a stroke partially caused by diabetes.

Gotti was open about his struggle to take insulin ... though he did say he was trying to change his diet in order to take better care of himself.

Gotti's family announced the news in a touching statement ... writing, he was surrounded by friends and family when he passed and he was "leaving behind a legacy that will forever resonate in the hearts of those who knew him and the countless lives he touched."

His funeral was held just last week ... and dozens of the biggest names in hip hop and R&B -- from Jay-Z and Fat Joe to Ja Rule and Ashanti -- showed up to pay their respects.

The medical examiner has not yet released a cause of death publicly ... but, Irv's brother says he knows exactly what led to his brother's passing.