Coolio Struggled with Severe Asthma, Friends Believe It Contributed to Death

Coolio appeared to be both happy and healthy in his final day of life, but friends say the rapper had severe asthma ... a condition they believe contributed to his death.

We've spoken with several sources close to the late rapper who each told us about his asthma, and how it was something he struggled with over the years. What's more, we know Coolio's family also told investigators looking into his death about his history with asthma.

We're told Coolio would always travel with several inhalers to keep his condition in check -- even using them on stage during some of his performances.

A recent study by the American Heart Association found people diagnosed with asthma have a higher risk of heart attack. Additionally, people who use a daily asthma medication were 60% more susceptible to heart attacks, strokes or other cardiac events.

TMZ broke the story -- Coolio died in the bathroom of a friend's Los Angeles home last week.

We're told before his death, he entered the bathroom, locked the door and apparently collapsed. Coolio's friend had to break down the door to get to him.