Infections caused by pathogenic microorganisms invading the body are another health risk associated with tatttoos and piercings. These infections can occur because the needles open the skin, allowing bacteria to enter the body, and can range from mild to life threatening.

Piercing have a greater tendency than tattoos to become infected. According to a Mayo Clinic article, studies show that up to 30 percent of piercings result in infections. This is because often the piercing result in infections. This is because often the piercing needle goes through flesh, whereas tattoo needles only penetrate the skin. Piercings are also prone to infections because they have long healing times, ranging from six weeks for an earlobe to six months for a navel piercing; because they rub against clothing; and because unsterilized jewerly may harbor bacteria. Navel piercings are among the most common piercings to result in infections because tight-fitting clothing inhibits air circulation, allowing moisture to collect in the piercing.

The American Academy of Dermatology warns people to be careful when getting any form body piercing, except ear piercing, because of possible skin infections. Typical symptoms include redness and swelling of the skin around the area that has been pierced and pus discharging from the piercing. Ointments are often used to cure minor infections.

More serious infections may require antibiotics or surgery and can result in long-lasting effects. For example, nipple piercing infections may affect a woman’s ability to breastfeed. Infections in the upper ear can also be very serious. Upper-ear cartilage does not have its own blood supply, so taking antibiotics is often ineffective because drugs cannot travel to the infection site. Upper-ear skin infections may require surgical drainage of pus. The most serious of these infections can permanently deform the ear.