Oh, God. We have a treasury of Britney-Spear-isn’t-doing-so-well stories for you today. The first comes from the National Enquirer, who claims that Britney “collapsed” while rehearsing with her dancers recently. It wasn’t just a collapse though – Britney totally fainted, and the reason being given in this story is Brit’s very secret… low blood sugar. How not scandalous. Why are they keeping that a secret?

In a terrifying medical scare, Britney Spears suddenly collapsed while rehearsing – and a doctor was rushed to her side. The pop tart was recently rehearsing new songs when she passed out as the dancers, as part of the routine, lifted her body while she lay sideways.

“She collapsed when the dancers went to put her back on her feet,” revealed the source. “She fell to the floor and landed on one of the dancer’s legs – and the dancer’s tennis shoe smacked Britney in the chest and on her face. It hit her chest with such a force that it caused a four-inch bruise.”

Everyone rushed over to Britney, and they realized she had fainted. Her father Jamie ended the rehearsal and immediately called a doctor.

The 27-year-old singer suffers from low blood sugar – a condition her father Jamie has been trying to keep secret, divulged a source. Although she’s physically strong, those close to Britney say she often doesn’t eat right or get enough rest. Plus, she’s under a lot of stress from the tour.

“Her schedule has wreaked havoc on her body,” the source divulged.

[From National Enquirer]

Unfortunately, there’s another theory floating around to explain this rash of Britney health problems – that I’ve yet to see verified anywhere other than the tabloids, so just keep that in mind. Sigh. I feel for Britney, and I want her to do well. For herself and for her little boys. This other theory about Britney’s health problems comes from Betty Confidential, which I’d never read before. Their theory makes a bit more sense than the “secret” low blood sugar. They claim that Britney’s been downing diet pills like tic tacs, washing them down with cocktails of energy drinks mixed with Red Bull. The combination of the diet pills, energy drinks and Red Bull is having a horrible interaction with Brit’s prescription medication – which we all know she’s taking, right? Cough cough lithium cough.

A touring Britney Spears is becoming overwhelmed by the demands of the road – despite help from her assistant, a nanny, friends and family. The pop star’s conservator-dad, Jamie, was especially alarmed when he caught his daughter popping over-the-counter diet pills, which she washed down with Red Bull, before a recent performance.

“Britney was definitely trying to get high by taking too many diet pills and energy drinks,” says a family insider. “Jamie thinks the combination of the two is making her whacked-out and, causing her to lash out in weird angry rampages.”

Given Britney’s tumultuous history, her reliance on diet pills is extremely risky, according to medical experts, especially when those pills are mixed with the kinds of prescription psychiatric medications that Britney is believed to be taking. “Britney uses green-tea supplements, [Lab 88’s herbal ephedra-free] Metabo Speed XXX, Dexatrim and apple cider vinegar to control her weight and energy levels,” adds the insider. “She also pours those 5-Hour energy drinks into her Red Bulls.”

The side effects of combining weight-loss aids with prescription medication can include increased anxiety, panic attacks and even seizures.

To stay out of trouble with her father, “Britney has her assistant buy the over-the-counter items for her,” says the source. “But she told Kevin about it because she doesn’t want him to think that she is addicted to harder stuff and take her two sons [Sean Preston and Jayden] away from her.”

Britney, whose tour began in London last month and will end in Australia in November, is feeling the stress of the constant traveling and performing, and it’s beginning to manifest itself physically.

“Britney has had a little problem lately with skin breakouts, but she is keeping it under control by using Proactiv,” adds the insider. “Since she has been so active, she’s fallen back to some of her old fast food habits, but her friends and family are trying to keep her from overindulging. Her younger sister, Jamie Lynn, has been trying to help her keep on track by making long-distance bets about who can eat the healthiest.”

Perhaps worst of all, Britney has been exhausting herself and not getting enough rest (and it’s exacerbated by her use of diet pills and Red Bull, which rev up the metabolism and make it hard to sleep), and this has been making her emotionally unstable.

Britney’s rep did not respond to a request for comment, but the insider says those closest to her fear a return of the Britney of a little over a year ago who went off the rails, memorably shaving her head and being admitted to a psych ward.

“Kevin has asked her to relax and take more time for herself and the boys,” says the source. “But she had a fit and went so far as to tell him to mind his own business. When Kevin told her she was acting like her old self, she really went nuts.”

The solution: Dad Jamie is considering hiring a full-time masseuse for Britney Spears and looking into getting her more psychiatric counseling. “As far as Kevin is concerned, it can’t come soon enough,” adds the insider. “He is genuinely afraid for her again.”

[From Betty Confidential]

It’s weird that I believe Betty Confidential’s scenario is a lot more likely, right? I can see Brit having no idea that diet pill abuse (over-the-counter speed) mixed with energy drinks (like a shot of caffeine in your eye) would mix poorly with whatever prescription drugs she’s on. Okay, everybody say a little prayer for Britney.

Here’s Britney leaving the Hyatt Grand Champion resort with Jayden James in Paris yesterday. Images thanks to Fame Pictures .