If you’re guilty of putting off changing your bedsheets, you’re not alone — but according to a microbiologist, it might be time to rethink your habits.
Dr. Primrose Freestone, professor of clinical microbiology at the University of Leicester, says bedsheets should be washed at least once a week — and even more frequently if you sleep with pets, tend to sweat a lot, or have been unwell.
In an article published by The Conversation, Dr. Freestone explains that while we sleep, our bodies release a mix of sweat, skin cells, and oils that soak into our bedding. Even if you go to bed clean, your skin naturally hosts bacteria and fungi — and by morning, that “biological soup” transfers onto your sheets.
“You might not notice it, but every night we shed hundreds of thousands of skin cells, produce oils, and sweat up to half a pint,” she wrote.
“Even clean sweat gets broken down by bacteria into smelly byproducts, which is why you may wake up with body odour despite showering.”
A 2022 YouGov poll found that only 28% of people in the UK wash their sheets weekly. Many go far longer — a practice Dr. Freestone warns can lead to a buildup of allergens, dust, and pollutants that affect breathing, trigger allergies, and worsen air quality.
And if you let your pet sleep in bed? That’s an added hygiene hazard.
“Pets bring in extra hair, dander, dirt, and sometimes even faecal traces,” she explained. “All of that means you should be washing your bedding more often.”
The takeaway? A clean bed isn’t just about comfort — it’s about protecting your health and improving sleep quality. So if you’ve been putting off laundry day, this might be your sign to strip those sheets.

