Not washing your bed sheets enough could lead to serious lung infections, warns expert – six signs you could be at risk

The Sun

09-07-2025

WE all have our unique bedtime routines, whether it's limiting screen time before bed, making sure your bedroom's the right temperature before slipping under the sheets, or deciding on a set bedtime.
And the same can be said when it comes to our sheets.
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While some people love fresh sheets once a week, others make changing their bedding a monthly ritual.
But how often should you really be washing them?
The feeling of clean, fresh sheets is a universally loved sensation, often described as comforting, relaxing, and conducive to better sleep.
But according to science, regular washing is more than just a question of cleanliness.
According to Primrose Freestone, a senior lecturer in clinical microbiology at the University of Leicester, people shed hundreds of thousands of skin cells each night, excrete oils from the sebaceous glands, and sweat up to half a pint of fluid.
And that's even after showering just before bed.
Writing for The Conversation, she explained: "Our skin hosts millions of bacteria and fungi, many of which are transferred onto sheets, pillows and duvets as we move during the night.
"That fresh sweat may be odourless, but bacteria on our skin, particularly staphylococci, break it down into smelly byproducts.
"This is often why you wake up with body odour, even if you went to bed clean."
But it's not just about these microbes.
Doctor shares why you must never wash clothes at 90 or 40 degrees & the right temperature for 'everything but gym gear'
During the day, our hair and bodies collect pollutants, dust, pollen and allergens, and this transfers onto our bedding, adds Freestone.
As well as triggering allergies and affecting our breathing, flakes of skin become food for dust mites.
Freestone warned: "The mites themselves aren't dangerous, but their faecal droppings are potent allergens that can aggravate eczema, asthma and allergic rhinitis."
Fungi can find your bed appealing too.
She added: "Some species, like aspergillus fumigatus, have been detected in used bed pillows and can cause serious lung infections, particularly in people with weakened immune systems."
Six signs you could be at risk of aspergillosis
Aspergillosis is an infection caused by breathing in spores of Aspergillus, a common mould.
While most people don't get sick from it, it can cause mild to severe illness.
There are six signs you could have aspergillosis, according to the NHS:
Shortness of breath
A cough - you may cough up blood or lumps of mucus
Wheezing
A high temperature
Losing weight without trying
Feeling tired
If you've had a cough for more than three weeks, have a lung condition that's getting worse or harder to control with your usual treatment, or have a weakened immune system and symptoms of aspergillosis, see a GP.
So how often should you wash your bedding?
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It depends on the type of bedding, says Freestone.
For sheets and pillowcases, wash them weekly, or every three to four days if you've been ill, sweat heavily, or share a bed with pets.
You should also wash therm at 60°C or higher with detergent to kill bacteria and dust mites.
Tumble drying or ironing is advised for deeper sanitation, and to target dust mites inside pillows, freeze them for at least eight hours.
When it comes to your mattress, vacuum this weekly, airing the mattress every few days.
Replacing your mattress every seven years can help maintain hygiene and support.
Pillows should be washed every four to six months - just check the wash label first.
Blankets and duvet covers should be done every two weeks, especially if your pet sleeps on them.
And duvets need washing every three to four months, depending on usage.