Mars would eventually drop out of high school to play guitar in several different bands throughout the ’70s (via All Music). Having no real success, Mars reinvented himself adopting the “Mick Mars” moniker and placed an ad in a Los Angeles paper calling himself a “loud, rude, and aggressive guitar player,” in search of a band. In 1981, Tommy Lee and Nikki Sixx responded and the only thing left for Motley Crüe to do was find a lead singer.

Around 17, according to Yahoo!, Mars was diagnosed with ankylosing spondylitis. A condition with no cure, ankylosing spondylitis causes chronic pain in the lower back, hips and legs. Mars describes the condition in the book “The Dirt: Confessions of the World’s Most Notorious Rock Band” this way:

“My hips started hurting so bad every time I turned my body that it felt like someone was igniting fireworks in my bones…At first, it felt like someone had plunged a knife into my back. But as the weeks passed, the pain kept moving around my back. Next, my stomach started burning, and I worried that my whole body was about to fall apart. I thought that there was a hole in my stomach, and acids were leaking out and destroying my bones and organs. I’d grab hold of doorknobs, anchor my legs into the ground, and pull with my hands to stretch my back and ease the pressure out.”

Over the years, the condition has caused major damage. A curvature in his spine causes Mars to hunch while playing and he’s lost 3 inches of height due to the compression on his lower spine.