Singer Toni Braxton seen wearing a heart monitor while performing on stage (photo)

Toni Braxton has been suffering from Lupus for a while now. (Lupus is a chronic inflammatory disease that occurs when your body's immune system attacks your own tissues and organs. It can damage any part of the body (skin, joints, and/or organs inside the body).

She's cancelled quite a number of shows as she battles the disease, which has been flaring up in recent weeks. And since Toni insisted on continuing with her shows which will take place almost every night through the middle of November, doctors, worried that she may go into cardiac arrest, while performing, have advised her to wear a heart monitor (that's it on her chest) to make sure that her vital signs are ok while she performs, while medical personnel will be backstage monitoring her vitals.