Singer Mariah Carey has revealed she has been living with bipolar disorder for years.

In an interview with People magazine, a candid Carey said she was first diagnosed with bipolar disorder after she was hospitalised for a physical and mental breakdown in 2001.

The 48-year-old admitted it was “the hardest couple of years I’ve been through”, and finally sought treatment after years of upheaval in her professional and personal life.

“Until recently I lived in denial and isolation and in constant fear someone would expose me,” Carey said.

“It was too heavy a burden to carry and I simply couldn’t do that anymore. I sought and received treatment, I put positive people around me and I got back to doing what I love – writing songs and making music.”

She added that for a long time she thought she had a severe sleep disorder.

“But it wasn’t normal insomnia and I wasn’t lying awake counting sheep,” Carey said.

“I was working and working and working … I was irritable and in constant fear of letting people down. It turns out that I was experiencing a form of mania. Eventually I would just hit a wall. I guess my depressive episodes were characterised by having very low energy.

“I would feel so lonely and sad — even guilty that I wasn’t doing what I needed to be doing for my career.”

Carey told People she is now in therapy and taking medication for bipolar II disorder, which involves periods of depression as well as hypomania.

She said the medication is working well.

“It’s not making me feel too tired or sluggish or anything like that,” the singer said. “Finding the proper balance is what is most important.”

I'm grateful to be sharing this part of my journey with you. @MrJessCagle @people https://t.co/jy1fOk4mMK pic.twitter.com/9E2D2OTARo

— Mariah Carey (@MariahCarey) April 11, 2018

Carey, who tweeted she was grateful to be sharing this part of her journey, said she decided to go public now because she’s “just in a really good place right now, where I’m comfortable discussing my struggles with bipolar II disorder.”