Among the most dangerous of piercing infections is endocarditis, a life-threatening infection of the heart valves. People with congenital heart disease who get pierced are particularly susceptible to getting endocarditis. Left untreated, the infection can fatally destroy the heart muscle. A Mayo Clinic study of 445 patients with congenital heart disease found that nearly one out of four of these patients developed endocarditis after getting pierced.

The January 2003 issue of the Pediatric Infectious Disease Journal stated that doctors are reporting incresing numbers of people developing infectious endocarditis after body piercing. The article included an example of a thirteen year old girl who became seriouslly ill one month after piecing her own navel. She was born with a heart malformation that been surgically corrected when she was tre years old. The girl said that she had removed her piercing after two days because it looked infected. A month later, she went to the doctor after running a fever for three days. Tests revealed that she had an infection in one of her heart’s valves. The girl was treated with heart surgery and antibiotics and realease from the hospital after twenty two days.

In addition to individuals with congenital heart disease, people with medical conditions such as diabetes and hemophilia are at a greater risk than most when getting pierced or tattooed. Diabetics take longer than nondiabetics to heal from cuts. The lengthier healing time increases their chances of getting an infection. While a diabetic’s main risk is infection, the danger for a hemophiiac is that he or she will lose excessive amounts of blood when getting pierced or tattooed. Typically when a person is cut, the blood’s ability to clot heals the wound, but a hemophiliac’s blood does not clot properly. This can result in great blood loss.

Like hemophiliacs, people taking mediciations that thin the blood are at risk of their blood not clotting when cut. Blood-thinning medications can make a person more likely to bleed heavily during and afer the tattoo or piercing process, and to experience excessive scabbing afterward.