Justin Bieber was finally diagnosed with 'super silent disease' after undergoing series of tests

In 2019, Justin Bieber underwent a series of intrusive medical tests after suffering extreme fatigue for some time. Weeks later, the results he'd long awaited finally arrived.

Tragically, however, the Canadian singer was then dealt a devastating diagnosis that would change his life forever.

A documentary released the same year covered Bieber, 31, discussing the news.

"So, I've been struggling with my energy for quite some time now, and I just haven't known why," he told a doctor on The Dark Season.

"I realised after a series of tests that I have what's called Lyme disease, which is a super silent disease that's not really very well known."

Bieber discussed the diagnosis on his documentary (The Dark Season/YouTube)

"It's very hard for doctors to test for it."

Also speaking on the documentary, Dr Erica Lehman - one of the 'Baby' hitmaker's physicians and a leader in his condition - explained: "Lyme disease is the fastest growing bacterial infection in the United States right now.

"We know that it can cause a whole spectrum of neuropsychiatric symptoms - mood changes, irritability, depression, anxiety.

"Justin fits the picture of these symptoms."

According to the NHS, the condition is caused by an infection prompted by a tick bite. As Dr Lehman explained, Lyme disease is surprisingly common, especially in the celebrity realm - with countless other stars having previously opened up about their own diagnosis's.

As well as being diagnosed with Lyme disease, the father-of-one - who shares infant son Jack with model wife Hailey Bieber - was informed by medics he suffered Epstein-Barr.

The condition is otherwise known as 'mono', short for infectious mononucleosis, but can also go by the 'kissing disease'.

In the UK, it's commonly referred to as 'glandular fever' - a viral infection that can trigger a fever, a sore throat, a loss of appetite, headaches and general fatigue.

Discussing this aspect of her husband's diagnosis, 28-year-old Hailey added in the documentary: "That in itself, mono, makes you really sick, and it makes you really tired. Some people can't get out of bed because of it."

Bieber went on to open up about the affect that such ailments had on his physical health.

"Basically, infections have played a big part in my acne and my overall toxins in by body," he explained, touching his face.

"Which just creates all this stuff. It feels good now to know why I fee so crappy all the time."

Bieber's wife Hailey also addressed his diagnosis's (The Dark Season/YouTube)

Rhode boss Hailey added: "He just felt so sick and there was no explanation for what was going on.

"So, now that we have all the answers and we know what it is and we know how to alleviate it and fix it, you know, I think he's honestly, not only healthier than he's ever been, but on the road to maintaining a healthier life than he's ever head, which is awesome."

Bieber also claimed he was 'committed' to seeing his health back on track, 'whatever I have to do'.

"I know ultimately, it's not only for me, but being the best me is going to help me be the best husband, the best father, the best friend I can possibly be."