Celine Dion reveals the heartbreaking news.

Celine Dion revealed on Instagram on Thursday that she has stiff person syndrome, an exceedingly rare neurological illness.

Celine details her therapy for stiff person syndrome after noting that “one in a million people” suffer from the condition.

As Celine Dion pointed out, stiff person syndrome is a rather unusual neurological disorder.

One of the symptoms of stiff person syndrome is muscle rigidity in the body and arms, which is usually triggered by stimuli such as noise, contact, and emotional discomfort. Celine’s condition is marked by muscle cramps and tightness.