Leona Lewis suffered a huge blow to her confidence when she diagnosed with Hashimoto's disease

She told the i newspaper: "It was just like: 'I feel awful'. I did not know what was going on. I was like: 'I'm sick. I'm really sick.' And I had to just stop ...

"I think it was a build-up. I had just not looked after myself how I probably should have. Body-wise, spiritually, mentally, physically, I just felt I was done. I needed to just go and look after myself.

"I think my confidence got a little bit knocked as well."

Leona previously opened up about how she changed her lifestyle after her diagnosis, revealing she turned to natural medicine, started eating healthily and using natural hair and beauty products.

She told Glamour magazine: "When I was first diagnosed, I was absolutely devastated; I felt very scared and alone until I began to research and understand how others were living with the disease ... I began taking medication but also turned to Ayurveda (my mum is a master herbalist) to help heal my body naturally. I just got to a point where I wanted to start over physically and emotionally."

She added: "I started eating better and I stopped straightening my hair. From there I began to shift my entire beauty routine. Having an autoimmune disease really made me take a long, hard look at how I can reduce the toxins I come into contact with daily. I started using natural skin care and hair products."