Most people know not to stick a finger up their nose while in public, mostly because of the embarrassment that follows if they get caught. It turns out, however, this etiquette no-no is not only bad for your social health, but it could put a dent in your physical health as well.
One study found an association between nose picking and nasal-dwelling Staphylococcus aureus, a strain of bacteria that can cause serious and sometimes antibiotic-resistant infections. It turns out that pickers are way more likely to have S. aureus hanging out in their nose holes than those who aren't mining for nasal gold [source: Heiman et al.]. Simply touching your nose, not to mention digging through it, is also a great way to transfer more common bugs like the flu [source: New York State Department of Health].
But before you reach for the tissues, consider this: A University of Saskatchewan professor hypothesizes that picking your nose — and even eating the product — might actually benefit your health in the long run. According to the professor — and the hygiene hypothesis — that's because introducing some bacteria into your body can provide your immune system with infection-related information it can use to fight them off later [source: CBC].
Either way, digging through your nose is still something best done in private.