Biting your nails can be a hard habit to break, but it can also be a painful one. Most of the time you might not even be aware that you’re doing it, although the consequences are pretty hard to miss. More often than not you can find yourself with sore, damaged skin around the nail which can increase the risk of infection due to it being an open wound (via Mayo Clinic).
Not only that, but biting your nails can affect other parts of your body as well, and can lead to dental problems, according to the Cleveland Clinic, as you end up using quite a large amount of force when chewing and biting them.
And seeing as the hands and fingers are one of the most common places to find germs, it’s inevitable for those germs to be transferred into the mouth and therefore increase the risk of catching colds and other types of viruses like COVID-19 or the flu.
Biting your nails can lead to infections
Colds and flu aren’t the only thing you can catch from biting your nails. As Time magazine notes, bacteria called enterobacteriaceae are often found on the hands and fingers after being in contact with an infected surface. This bacteria, which includes salmonella and E. coli, thrive under the crevice between the nail tips. If you bite your nails, this bacteria is then transferred to your mouth and gut leading to cases of gastro-intestinal infections which can include diarrhoea, abdominal pain, and vomiting.
There’s another bacterial infection common to nail biters — paronychia. This infection usually occurs on the skin around the cuticle or up the sides of a nail, and usually presents with inflammation around the affected site. According to DermNet NZ, the bacterial infection is caused by a break in the skin mixed with Staphylococcus aureus, Streptococcus pyogense, Pseudomonas, and other bacterial pathogens like the cold sore virus and yeast.