Body piercing in places other than the ear often leads to complications like infections, swelling and bleeding, a new study shows.

The data, compiled in Britain by the Health Protection Agency and the London School of Hygiene and Tropical Medicine, show that 25 percent of piercings in body areas other than the earlobe lead to complications, with one in 100 piercings resulting in a hospital admission. More than 10,000 people ages 16 and older took part in the survey, which was published online today by the British Medical Journal. A 2002 study of American college students also reported a high rate of complications, with 17 percent of students complaining of problems, including bleeding and infection. Nipple piercing appeared to be the most risky, with a 21 percent rate of bleeding or injury.

About 10 percent of the adult population in Britain has a non-earlobe body piercing. Prevalence estimates in the United States are harder to come by, but the 2002 report, published in the Mayo Clinic Proceedings, found that 51 percent of the college students surveyed had some sort of piercing, not counting pierced earlobes among the women.

In that study, 38 percent of male students had pierced ears, either in the lobe or elsewhere, whereas 4 percent had pierced tongues and 3 percent had pierced nipples. Among female students, pierced earlobes weren’t counted, but 29 percent had piercings elsewhere on their ears. Another 16 percent had pierced tongues, 6 percent had pierced nipples and 32 percent had pierced navels.

In the British study, 16-year-olds with piercings were also more likely to suffer from complications, with almost a third reporting problems and 15 percent seeking professional help. Although most piercings were performed in specialist piercing shops, the researchers noted that a “worrying” 9 percent of tongue piercings were performed by nonspecialists. In every anatomical site, including the tongue and genital areas, the study authors said they found a number of people who had performed the piercing themselves or had it done by a friend or relative.

The most common problems with piercings were swelling, infection and bleeding. Almost half of tongue piercings resulted in complications in the British survey.

The growing popularity of body piercings could “place a significant burden on health services for many years,” the researchers said.