RALEIGH, North Carolina (WNCN) — Pop star Justin Bieber’s announcement that he’s postponing his tour after half of his face became paralyzed has people wondering about the condition behind it.

The condition is called Ramsay Hunt syndrome, and it’s just one of many causes of facial paralysis.

The multi-Grammy winner said in a video he posted on Instagram that he has the condition, which causes facial paralysis and affects nerves in the face through a shingles outbreak.

Bieber’s post came after he canceled his shows in Toronto and Washington, D.C. The singer demonstrated in the video that he could barely move one side of his face, calling the ailment “pretty serious.”

Dr. Matthew Miller, director of the University of North Carolina at Chapel Hill Facial Nerve Center, treats people with facial paralysis caused by the condition.

“The easiest way to think about Ramsay Hunt syndrome is shingles of the facial nerve,” Miller explained.

So, it’s caused by the same virus that causes chicken pox.

“Once you beat that chickenpox infection, that virus always lives within you,” Miller said.

The virus can reactivate at times of stress, leading to Ramsay Hunt syndrome.

“The most obvious symptom of it is partial or complete facial paralysis on one side of your face,” said Miller, adding that other symptoms can include a blistering rash near the ear, intense ear pain, hearing loss, and dizziness.

Not everyone has all of the symptoms. Ramsay Hunt is just one of many conditions that can cause facial paralysis.

“I think we have 30 different causes of facial paralysis we are treating at the UNC Facial Nerve Center,” Miller said.

For people experiencing facial paralysis, Miller emphasized that it’s important to get diagnosed as quickly as possible because the treatment depends on the cause.

Whatever the cause, Miller knows how difficult it is to live with facial paralysis. He experienced it himself after an accident in college.

“On a bicycle ride, a training ride, I collided headfirst with a car,” he recalled. “I was left with severe traumatic brain injury and pan facial fractures, which is the medical term for I had my face crushed.”

“I did have a complete left-sided facial paralysis really for six or seven months before I slowly started to recover,” Miller added. “I can remember just how devastating that was, how devastating it was to have people staring at me, really ignoring what I’m saying because they’re wondering what’s going on with my face.”

Miller still receives treatment and says there’s hope for those with facial paralysis, no matter the cause or how long the paralysis has lasted.

“We know so much more today than we did five years ago, 10 years ago,” he said. “We have so many ways to help you get better.”

Bieber said he’s unsure how long he’ll take to heal. But he appeared positive about making a full recovery through rest and therapy.

“I’ll be using this time to just rest and relax and get back to a hundred percent, so that I can do what I was born to do,” he said.

The Associated Press contributed to this report.