An expert in microbiology has warned that not washing your bed sheets can impact your health and even 'make breathing actually quite difficult'. 

How often a person washes their bed sheets varies greatly; changing with the seasons, as well as depending on what a person gets up to in their bed once the curtains are drawn. 

On Newstalk Breakfast, University of Leicester Associate Professor in Clinical Microbiology  Dr Primrose Freestone said bed sheets get dirty very quickly. 

“You'll deposit about a pint, half a pint or so of sweat, more if the weather is actually warm,” she explained. 

“That is eaten by the bacteria and fungi that are actually on your sheets. 

“At the same time, the skin cells you deposited are actually food for your house dust mites.

“And those will actually produce dung that can actually make your sort of breathing actually quite difficult, the respiratory irritants.”

Dr Freestone added that sleep is “absolutely essential for your mental and physical well-being” and that clean bed sheets will help that. 

She also cautioned against a build up of fungi on unwashed bed sheets. 

“The world is actually full of fungal spores and you have them on your body, in your hair,” she said. 

“They're part of your natural microbiome, the microorganisms that naturally live on you. 

“They will also eat your skin cells and sort of nibble on your sort of dried sweat. 

“And fungi especially can actually cause breathing problems.” 

An woman sleeping on a mattress. Picture by: Antonio Guillem Fernández / Alamy Stock Photo

When asked how often people should wash their bed sheets, Dr Freestone said it depends on how clean a person is when they go to bed. 

“The fact is, even if you just showered, you will still deposit the skin cells and you'll still sweat,” she said. 

“If you have an infection, particularly a virus, an upset stomach, normally the NHS in this country recommends washing sheets at a high temperature, at least 60 degrees with a detergent every week. 

“If you're unwell, it's normally every three to four days. 

“If you have pets or, I have to say, small children in your bed, you might actually have to wash them once or twice a week.”

Main image: A couple in bed together. Picture by: Alamy.com.