CANADIAN SINGER JUSTIN Bieber has announced that he has Lyme disease.

In a post on Instagram, the 25-year-old said he will address his struggle with the illness, which is contracted through a tick bite, in a YouTube documentary.

“It’s been a rough couple years but getting the right treatment that will help treat this so far incurable disease and I will be back and better than ever,” he said.

He also called out critics who he says have been unfairly commenting on his looks by saying he looks like he has a drug problem.

“They failed to realise I’ve been recently diagnosed with Lyme disease, not only that but had a serious case of chronic mono which affected my, skin, brain function, energy, and overall health.”

The disease is transmitted to humans through infected ticks, and symptoms include fever, chills, headache, fatigue, joint aches and a “bull’s-eye” rash that occurs in 70 to 80 percent of infections.

Most people who are treated with antibiotics early fully recover, according to the CDC, although the infection can become severe or prolonged in some cases.

The photo portion of Bieber’s post shows an article which reports that the YouTube documentary about his ordeal will be released on 27 January.

“You can learn all that I’ve been battling and overcoming!!” he wrote on Instagram.

He spent much of last year suffering but undiagnosed, TMZ reported, until doctors figured out what was wrong.

In subsequent Instagram posts and on his Instagram story later in the day, Bieber thanked his fans for supporting his new song released last week.

And the Canadian suggested his condition is improving, posting a meme video of a little girl dancing with the caption “But now this is how I’m feelin’”.

- © AFP 2019