Pop singer Justin Bieber announced in an Instagram post on Friday that he has Ramsay Hunt syndrome, a rare condition which is causing him partial facial paralysis. 

The 28-year-old also said he would cancel his upcoming tour dates as he is "physically, obviously not capable of doing them".

"As you can see, this eye is not blinking, I can't smile on this side of my face, this nostril will not move," Mr Bieber explained in the Instagram video.

What is Ramsay Hunt syndrome?
According to National Library of Medicine of the United States government, the Ramsay Hunt syndrome neurological condition caused by varicella-zoster virus .

Varicella-zoster is the same virus that causes chickenpox in children and shingles in adults. When the nerves are inflamed, they lose their ability to function properly, which can cause facial palsy.

The illness can also result in painful, blistering rashes affecting the ear and the mouth.

The symptoms of Ramsay Hunt syndrome?
The signs and symptoms of Ramsey Hunt syndrome can include pain, vertigo, hearing loss, sensitivity to sound, tinnitus, and loss of taste, as per a Morbidity.

Additional symptoms include a change in taste sensation, dry eye, tearing, hyperacusis, nasal obstruction, and dysarthria.

The progression of disease
The disease progresses rapidly and fully manifests itself in two to three days. While initially the patient may complain of difficulty in closing eye and facial weakness.

Treatment of Ramsay Hunt syndrome
Antihistamines can help with vertigo symptoms, such as dizziness or feeling like the room is spinning, according to Healthline. Eye drops can help lubricated.