“Firmer mattresses tend to be better for chronic pain because they provide adequate support,” says Michael Grandner, PhD, director of the Sleep and Health Research Program at the University of Arizona College of Medicine.
But while that’s true generally, Grandner says the right mattress for YOU depends on many different factors—like where you experience pain, your preferred sleep position, the thickness and firmness of your pillow, and a whole lot else.
His number-one piece of advice when it comes to choosing a mattress? “I recommend something with a good return policy,” he says.
You can spend all day reading mattress reviews. But until you actually sleep on the thing for a week or two, you won’t know if it’s a good fit for your needs.
With that in mind, here are some surprising warning signs that you should be thinking about a new mattress. If you’re experiencing any of these issues, it’s probably time to replace yours.
1. You wake up with a stuffy nose
Dust mites are microscopic insects that feed on mildew-degraded house dust. If you have dust, you have dust mites.
Many people are allergic to these tiny bugs. In fact, they may be the most common cause of year-round allergies, according to the Asthma and Allergy Foundation of America (AAFA). Dust-mite allergy symptoms include a runny nose, sneezing, watery eyes, and an itchy mouth or throat, the AAFA reports.
If you wake up with those symptoms, your mattress may be to blame. A 2010 study from German researchers found people who started sleeping on mattress toppers that reduced the presence of dust mites and mildew enjoyed a 43% drop in allergy symptoms.
Along with washing your pillowcases and sheets at least once a week to rid them of mites and other allergens, buying an allergen-blocking mattress could also help, the research suggests.
2. Your libido is low
A non-existent sex drive is one of the sneakier signs that you’re not getting good-quality sleep. And both night sweats and sleep disturbances—caused in some cases by a too-warm sleeping environment—are linked to a loss of libido, finds a 2007 study in the American Journal of Obstetrics and Gynecology.
Buying a mattress (and cooling sheets or pillows) that helps keep you from overheating at night is another good way to safeguard your ZZZs—and your sex drive.
3. Your skin doesn't look or feel so great
Poor-quality sleep is associated with a surge in stress-related hormones like cortisol, shows a study in the journal Sleep Medicine Clinics. More research shows this uptick in cortisol and the systemic inflammation it causes can promote wrinkles, a loss of skin firmness and elasticity, dull skin, and itchy skin conditions like eczema.
Old mattresses may be one cause of poor sleep and stress. A recent study in the Journal of Chiropractic Medicine found the average person’s mattress was 9.5 years old, and that a switch to a newer mattress both improved sleep and lowered stress.
While the study authors say there’s not enough research to show that one type of mattress is ideal for every sleeper, their experiment linked improved sleep quality with new medium-firm mattresses that featured foam-encased springs.
4. It takes you an hour or more to fall asleep
One measure of sleep quality is something sleep researchers call “sleep onset latency”—or the amount of time a person lies in bed before finally drifting off.
While you may (rightfully) blame your inability to fall asleep on things like your bedtime smartphone habit, or your messy room, a too-firm mattress may also be to blame, shows a 2015 study in Sleep Science.
That study found that when a group of elderly people switched from a “high firm” mattress to a “medium firm” mattress, the average time it took them to fall asleep fell from an average of 67 minutes to just 21 minutes. Measures of neck and back pain also dropped more than 50% after the study participants slept on the medium-firm mattresses for four weeks, the study shows.
5. You feel groggy even after a full night's sleep
Just as a dust-mite allergy could cause you to wake up with symptoms like a stuffy nose or itchy throat, the presence of mold or bacteria in your mattress could trigger sleep apnea, nighttime asthma, or other “sleep-disordered breathing” issues, finds a 2013 study in the Journal of Allergy and Clinical Immunology.
The result: you’re wiped out during the day even when you slept a solid eight hours or more. More research shows asthma-causing mattress microbes are super common.
Along with cleaning your sheets and pillowcases regularly, you can help prevent bacteria and other microorganisms from building up in your mattress and pillows by protecting them with allergen-proof covers.
This article originally appeared on Prevention