Canadian pop singer Justin Bieber has told fans that he is battling Lyme disease.

Bieber, 25, posted a message on Instagram saying that he had been diagnosed with the bacterial infection and that it had been “a rough couple of years”.

However, he vowed to be “back and better than ever”.

Bieber told his 124 million followers: “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.

“These things will be explained further in a docu series I’m putting on YouTube shortly.. you can learn all that I’ve been battling and OVERCOMING!!”

He added: “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 NO CAP.”

Bieber revealed last month that he is to star in a documentary series which will give fans a look at the making of his first new album in more than four years.

Lyme disease can cause a range of debilitating symptoms from fatigue and joint pain to heart problems and partial paralysis.

The disease has struck numerous celebrities in recent years. In 2015 it was revealed model Bella Hadid had the disease; the same year that singer Avril Lavigne was also diagnosed with it. In 2016 actor Kris Kristofferson discovered the memory loss he had been suffering from was due to the disease.