When was the last time you washed your pyjamas?
A week ago? Or maybe a fortnight? Or even a month?
While you might think they're clean, chances are they're really, really not. In fact your dirty pjs could be causing all manner of health problems including cystitis, allergies and even skin complaints such as acne.
A study of over 2500 young people, found that the majority of people wear the same pyjamas for more than two weeks at a time.
For 78% of men, the main reason for their lack of frequent pyjama-washing was because someone else did the laundry and, therefore, they had no control over it. *Rolls eyes*
Meanwhile, women argued that they swap between different pyjamas during the week and then end up forgetting how long they'd worn them for.
The sniff test appeared to be the most common method for testing pyjama dirtiness, with 50% of men and 41% of women saying that if their pyjamas didn't smell bad they wouldn't bother changing them.
But, you can't sniff out bacteria, and that's the main issue here, as the build up of bacteria - particularly in sebaceous sites on your skin (the oily bits) - can cause acne.
Many people carry staphylococcus bacteria, which can cause infections if they get into cuts and bruises. Additionally, E Coli bacteria, which is found in the bowel, can cause infections such as cystitis if they get into the urinary tract.
Additionally, and just to make you really cringe, the human body sheds between 30,000-40,000 skin cells per hour. Built up over two weeks, this is a ridiculous amount of skin lingering in your PJs.
With all of this dead skin and bacteria knocking about, it might not surprise you to find that when it comes to washing your pyjamas, the debris is then transferred across to the rest of your laundry too.
To prevent this, Professor Sally Bloomfield of the London School of Hygiene & Tropical Medicine suggests washing your pyjamas at least once a week to keep clean and prevent infection.
And it's not just pyjamas that people have an aversion to washing either. Yes, the horror story continues...
One in five people suggest that they don't even change their bed sheets after a month has passed. All of the dead skin cells which build up in your bed then attract hungry dust mites.
In fact, old mattresses can have up to 10 million of the little skin-munchers crawling around.
As for the big finale, 10% of your pillow weight is probably made up of dust mites and their poo, which, if you're not careful, can cause allergies, rashes and asthma.
So it's worth replacing your pillows every six months too.