Justin Bieber has revealed that he has been diagnosed with Lyme disease.

In a post on his Instagram account, the 25-year-old singer says that while some people have been criticizing his looks and accusing him of being on meth, he has actually been battling Lyme disease.

Bieber also says he recently had a serious case of chronic mononucleosis, which affected his “skin, brain function, energy, and overall health.”

Lyme disease is an infectious disease caused by the Borrelia bacterium which is spread by ticks. Most people with the disease experience flu-like symptoms including fever, chills, headache, fatigue, rash, and muscle and joint aches.

Canadian singers Shania Twain and Avril Lavigne have also battled the disease.

Bieber says he’ll explain further in his upcoming YouTube series, “Justin Bieber: Seasons,” which comes out January 27.

The Stratford, Ont.-native says it’s been a rough couple of years but he’s been battling and overcoming.