"While a lot of people kept saying Justin Bieber looks like sh*t, on meth etc. they failed to realize 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," Bieber tweeted.
Following the news about Bieber's health, 35-year-old Lavigne took to Instagram to show her support. In April 2015, Lavigne revealed her own Lyme disease diagnosis that left her bedridden for five months.
"Today @JustinBieber shared that he has Lyme disease. There are too many people that have this debilitating disease!" she wrote. "People I love and care about and many friends and fans I have crossed paths with. To everyone affected by Lyme, I want to tell you that there is HOPE. Because Lyme is a daily struggle, for the better part of two years, I was really sick and fighting for my life."
"Writing #HeadAboveWater helped me get through the worst of it, but the bad days still come and go," she continued. "At the time, putting together my album saved my life. I needed to tell my story and to be able to share my experiences with others. Lyme disease is in all 50 states in the US and in EVERY country in the world, except Antarctica. It is a global pandemic but NOT a global priority. I never want others to suffer the way that I did, and because of that it is now my mission to raise awareness & funds that will help eradicate this life-altering disease. Portions of proceeds from every show on the rest of the #HeadAboveWater tour and merch sales will continue to go directly to Lyme disease. I will continue to fight and to support!"
In June 2015, Lavigne appeared on Good Morning America and broke down in tears over her battle with the disease. According to the Centers for Disease Control and Prevention, Lyme disease is transmitted to humans through the bite of infected black-legged ticks. Typical symptoms include fever, headache, fatigue, and a skin rash called erythema migrans.
"I was in Los Angeles, literally, like, the worst time in my life and I was seeing, like, every specialist and literally, the top doctors, and they were so stupid, and they would pull up their computer and be like, 'chronic fatigue syndrome,' or 'Why don't you try to get out of bed Avril, and just play the piano? Are you depressed?'" Lavigne said. "This is what they do to a lot of people who have Lyme disease. They don't have an answer for them so they tell them, like, 'You're crazy.'"
Other celebs who have been battling Lyme disease include Shania Twain, and Yolanda and Bella Hadid.
On Wednesday, Bieber's wife, Hailey, thanked the Hadid family for educating her on Lyme disease and also reached out to Lavigne on Twitter.
"And sending so much love to @AvrilLavigne thank you for all you do to educate people about Lyme," she wrote. "You’re amazing."
"For those who are trying to downplay the severity of Lyme disease," she began. "Please do your research and listen to the stories of people who have suffered with it for years. Making fun of and belittling a disease you don’t understand is never the way, all it takes is educating yourself."
Meanwhile, on Wednesday, 25-year-old Bieber assured fans that he was "battling and overcoming."
"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," he tweeted.