Kim Kardashian had a "mental breakdown" days before her bar exam.

The 45-year-old reality star - who spent six years preparing to become a lawyer before taking the test over the summer - admitted last month she had failed the exam, and she has revealed how much she was struggling in the build up to the assessment.

In the latest episode of The Kardashians - which including footage filming just nine days before the test - she said: "I'm absolutely gonna cry, cause it's f****** exhausting."

Kim admitted she had "hit a wall" with her preparation for the test.

She added: "I threw my back out, and it's like, every time I think I get to another step, something pulls me back.

"There's all these f****** roadblocks, and I'm not a pity party kind of girl, but last night, I was like, why the f*** is this happening?"

Kim revealed she was also dealing with a back injury, which meant she could "hardly walk" or even sit down.

She was "shocked" by how tired she was, and revealed she had been warned that "everyone, before, they take the bar, has a mental breakdown".

She said: "I just knew that wasn't me, 'cause I'm not that person, but I get it. It's really a lot. Now I really, really get it.

"I had no clue it was gonna be this emotional," she continued. "I don't know how I can get any more information into my brain."

Before failing the test, Kim insisted she had no plans to retake the exam if she didn't pass.

She said: "I really want it, and if I don't pass, I don't think I would take it again. I wouldn't have the time for a few years, and then I'm older and then my brain capacity is different."

However, last month Kim insisted she wasn't "giving up" after the setback.

Referencing her role in Ryan Murphy's legal drama All's Fair, she quipped on Instagram: "Well...I'm not a lawyer yet, I just play a very well-dressed one on TV.

"Six years into this law journey, and I'm still all in until I pass the bar.

"Thank you to everyone who has supported and encouraged me along the way so far. Failing short isn't failure -- it's fuel. I was so close to passing the exam and that only motivated me even more. Let's go!"