During the 1990s, Boyz II Men was a quartet with bass singer Michael McCary, who left the group in 2003 due to health issues that were diagnosed as multiple sclerosis.

In 2003, McCary left Boyz II Men due to back spasms that were eventually and ultimately diagnosed as multiple sclerosis. McCary kept his condition from the other band members and did not make it public until 2016.

By the age of 22, however, McCary's symptoms had worsened dramatically and "started going full scale." He eventually left the band in 2003, after more than two decades performing together. Doctors told him aggravating a "locked" nerve in his back could potentially leave him paralyzed, according to McCary.