There are probably hundreds of 'useless' tattoos out there, but there is one in particular that you might want to refrain from getting. It is the DNR tattoo, or do not resuscitate tattoo. Some people for religious, personal, or whatever reasons have decided that in the event of a medical emergency, they do not want to be brought back from the dead but would prefer to die because, well, such is life or in this case, death. In order to make that wish clear, they will often get a DNR tattoo across the chest somewhere because generally when one is in the Emergency rooms, you're stripped bear so emergency personnel can perform medical tests and procedures without the encumbrance of clothing. Presumably these medical professionals would of course see this tattoo and stop right away and just let you pass on, right?
Wrong. Legally speaking, tattoos are not, well, legally binding. Suppose when you were 20 you were going through a terrible fight with stage 3 cancer and after so many treatments, you decided you wanted a DNR order tattooed on your chest because you didn't want any more treatments especially if they were seemingly failing and you wanted the end to be the end. Now it's 10 years later, you're very much alive, you have a family, a job, a life, but that tattoo is there, though now, with presumably a lot more to live for, you just haven't gotten round to removing the tattoo or have just forgot about it because you haven't had many brushes with death lately. How on earth is a doctor or an EMT or nurse supposed to know whether you feel that way today because of that tattoo or this was some dumb or funny tattoo you got as a kid? They can't.
Did you know CPR is the ONLY medical procedure that can be preformed on you without consent of a doctor? It is so crucial that really and truly doctors and nurses have no time to decide whether that tattoo is real, or let alone to begin to search for tattoos on your body when you're flat lining. They are legally bound by professional standards to do everything in their power to try and save your life until a legal document can be shown that says you have a DNR order which could take quite a while especially if you're say on vacation in another country and something happens to you. If you really and truly do want a legally binding DNR, you must get legal paper work filed with your doctor for which he or she must have already signed off on it prior to you being in an emergency situation and on your end, informed family, friend, or executives of your living will that these are your wishes. Add to that, most docs aren't going to just sign off on one because you asked. Usually that kind of order is only granted to elderly and/or persons in hospice care and those with terminal illnesses because that doctor would essentially be signing your death warrant and they don't usually do that for healthy people.
Though a DNR tattoo may be completely useless, medical alert tattoos can be helpful to some degree. For example if you are a type 1 diabetic, or you have some type of severe allergy to medication, food, bees, clearly tattooing these things right near the crux of your arm where an IV would be started can be helpful provided you don't have a million other linking tattoos and that it is written clearly and big enough to read without a magnifier. However, you have to know that millions of people with all types of medical issues do not wear medic alert bracelets, or have tattoos, or are even aware of their conditions and these same medical persons must know how to treat and diagnose conditions without a stitch of information or paperwork or jewelry on those people, so whether you get that tattoo or not, EMTs and doctors and such are trained to figure out what's wrong with you without the ink, and many due to the life and death situation, aren't going to spend an extra second checking to see if you have a bracelet or a tattoo on you.