Almost half of people between 18 and 35 have tattoos, and almost one in four regrets it, according to a 2016 Harris Poll. Based on an estimate of about 60 million people in that age group, that would mean that about 7.5 million people have tattoo regret.

As a primary care physician, I’ve noticed anecdotally that many of my younger patients have regrets about their tattoos. When I ask about them, many say that they got them when they were young, and at the time put little or no research into the decision.

With no source (reliable or otherwise) of tattoo information to suggest to my patients, I began to investigate the topic myself. My goal was to write a quick reference for teens that reviewed the health and social issues they might encounter after getting a tattoo.

What I found was myriad unexpected and sometimes shocking concerns that everyone should know. To my surprise, there were a host of reports of ink complications, infections, toxin effects, scarring, burns, chronic irritations and much more.