WATCH: The filth lurking in your bed is the stuff of nightmares

We love our beds. But just how clean is yours? It could be what's making you sick. Dust mites, which are in 4 out of 5 American households, won't hurt you. But dust mite droppings, which are part of the whole "microscopic bug package," are highly allergenic. Fortunately, you can reduce their numbers by damp mopping your floors and changing out your rugs.

One study found 47 different species of fungi in a random sampling of 10 regularly used pillows. Breathing that in every night is especially harmful for those with respiratory problems, like asthma. Had your pillow for more than 2 years? It's time to get a new one.

But it's not just tiny, invisible intruders in your bedroom. You can love to cuddle with your pups in bed- but your body can still be irritated by their dander, urine, and saliva. Experts recommend pet owners should vacuum their mattresses and pillows at least once a week. Non-pet owners should, too. Because the final unhygienic element in your bed is you. Adults can produce up to 26 gallons of sweat every year. A third of your life is spent sleeping and sweating in bed. Pathogenic germs like strep or staph can transfer to your bedding and infect you or your partner.

But no need to set your mattress on fire and start over. Listen to your mother and wash and change your sheets once a week. You need to sleep well for optimal health- and a big part of that is doing it in a clean, hygienic bed.