Actress Denise Richards has an unusual phobia - she's petrified of vomiting.

The screen beauty, who's currently working on saving her marriage to Charlie Sheen, admits that the very thought of throwing up terrifies her, and she constantly takes measures to ensure she'll never have to go through the experience.

She says, "I have a throw-up phobia. I'm terrified of throwing up. I don't know why. It's beyond not enjoying it, (I have) a fear of it. Terrified, ever since I was little.

"If someone's around me throwing up or sick, I find out if it's the stomach flu or food poisoning. Like, at work a girl was sick and I asked her... Food poisoning, I'm okay, because I won't catch it. Isn't that terrible?

"I asked my parents (what caused my phobia). I think something happened in my childhood. I don't know. I'm terrified of it."

And Richards, who admits she religiously burns her chicken to avoid salmonella poisoning, is prepared for the first time she has to experience her two young daughters vomiting: "I guess I'm gonna have to get out the rubber gloves and a mask, or something, and then pay for their therapy later."