You might keep your phone in your bag, or on your desk, or in your pocket, but chances are it spends an increasingly large portion of the day in one very dirty place: your hand.More than half of smartphone owners check their phones a few times per hour or more, according to Gallup.A Deloitte survey cited by Time found that the average person checks their phone 46 times a dayand young people check their phones far more.The thing is, every time you touch your phone, you transfer bacteria that you've picked up as you've gone about your day.That includes the little microbes you encountered while clinging to subway poles, opening the bathroom door, orshuddertouching your kitchensponge. Plus, anytime you speak or cough with your phone near your mouth, you'll load it up with whatever happens to be living in your respiratory tract."It is wise to periodically clean your phone," says Philip Tierno, a microbiologist and pathologist at the New York University School of Medicine. "I [clean] mine at the end of each day with just a wipe."Tierno says thatstudies have found many different types of bacteria and viruses on phones, but that it's common to find bacteria that live on people's skin, in their respiratory tract, and bacteria that live in fecal matter.And while mostof those bacteria won't be pathogens that make you sick, they're not all completely harmless. Various studies have found E. coli, MRSA, Streptococcus, and many other species living on mobile phones.In some cases, you might need to be exposed to thousands of those microbes before you get sick, so their mere presence isn't necessarily a cause for concern. But Tierno says that in the case of some pathogens, like norovirus (which has also been found on phones), just one little virion might be enough to leave you miserable and vomiting.Fortunately, you can clean your device. A microfiber cloth will remove most(though not all) bacteria. And while manufacturers generally don't recommend using harsh cleaners like alcohol on your delicate touchscreen, there are other recommended cleaning products that can get the job done.Tierno says that in general, it's okay if you miss a day of cleaning every so often. But still."If youre not cleaning your phone, you should," he says.Join the conversation about this storyNOW WATCH: The uncomfortable truth about how dirty your phone is Click here to read full news..