Many people who experience health problems after having an intimate body piercing do not seek medical help, research suggests.
Nipple piercing can lead to infections
Pittsburgh's Carlow University focused on 146 men and women with nipple and genital piercings.
They found a majority of people developed problems such as infections and changes to urine flow, but only 3% sought medical advice.
The research is published in the Journal of Advanced Nursing.
Of those who took part in the study, 43% had nipple piercings, 25% had genital piercings and 32% had both.
The team found that 66% of people with nipple piercings and 52% of those with genital piercings had developed health problems.
The most common problems with nipple piercings were sensitivity (37%), skin irritation (21%) and infections (21%).
For male genital piercings the top problems were urinary flow changes (39%) and sensitivity (31%).
While more than half of people (54%) discussed their problems with their piercer, only a tiny fraction sought professional medical advice.
Despite the problems, most people liked their piercings - ranging from 73% to 90%, depending on piercing type - while 87% said their partner was positive about it.
Professor Carol Caliendo, of Carlow University in Pittsburgh, said: "It's clear from our study that when people experience problems with intimate body piercing they are reluctant to consult healthcare professionals and we need to encourage people to come forward.
"We are particularly concerned about the urinary flow changes reported by men after genital piercings.
"It's clearly an issue that needs to be highlighted with men who have had, or are considering, piercings and the people who carry them out."
Kathy French, a sexual health adviser for the Royal College of Nursing, said people should only go to an accredited practitioner to get a body piercing done.
"There is probably a fair level of embarrassment about problems that may arise, and probably a fair amount of ignorance among health professionals as well," she said.
"We need to raise awareness of this issue. It is not just about things that might go wrong.
"For instance there are issues such as whether it is safe to use condoms with pierced genitals."