Few people realise how many skin cells and other nasties build up in a bed over time. Photo / Getty

We spend about a third of our day between the sheets.

Over time, our bed becomes a haven for bacteria, dirt and other nasties to build up while we sleep.

According to Dr Philip Tierno, Jr., Director of clinical microbiology and immunology at New York University's Langone Medical Center, your bed sheets can accumulate an array of dead skin, bacteria, fungus and mites after just one night's sleep.

With the average person producing more than 98 litres of sweat each year, dirty bedding can cause breakouts, skin irritations and even make us sick.

In a recent study, researchers found that feather and synthetic pillows between 1.5 and 20 years old can contain between four and 17 different species of fungus.

In short, your bed can be a pretty filthy place.

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And according to cleaning guru Shannon Lush - quite a few of us are failing when it comes to keeping our linen clean.

"If you're showering once a day, you can wash your sheets weekly," Ms Lush told news.com.au.

"However, pillowcases should be changed every second day without fail. It's against your face, and your hair holds more dirt than anywhere else on the body. It's like a mop."

Ms Lush said very few people realise how much skin cells and other nasties build up in a bed over time, recommending we wash the duvet every month along with our pillows.

"Most people don't wash their pillows enough, and it's really vile," Lush said.

"It collects old skin cells, which we shed especially when we are asleep. The pillow is a major cause of blackheads.

"Human skin is protein, and lots of nasties live in protein. If you don't use protectors, that will go in to the bedding. And you wouldn't leave a steak in the middle of the bed, would you?"

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Ms Lush said the best way to wash your duvet - which can often be a challenge when attempted alone - is in the bath.

"Put a small amount of cheap shampoo in the bath, and use blood heat water (luke warm)," she explained.

"Stomp up and down on the [duvet], then rinse in the same temperature water.
"Put on a clothes line and hang it in a U shape, that way it doesn't compact."

When it comes to washing sheets, Ms Lush advised not to pour any rice water down the sink - because that's her secret ingredient to achieving "five-star hotel quality linen".

"I always put rice water in to the final rinse of my sheet wash," she explained.

"After cooking the rice, save that water and dilute it one part rice water to four parts regular water.

"Keep the mixture in a jar in the laundry, and add two tablespoons during the final rinse.

"That will give your sheets that same crisp feeling you get at a hotel, and will absorb sweat better and even treat your skin."

- news.com.au