1) Risk of infection. As you may know, tattoos work by piercing the skin with a needle and injecting little gobs of ink. If the tattoo artist is not sanitary and does not clean his equipment after every use and the needle is not properly sterilized, you may get infected with a wide range of diseases.
2) Allergic reactions. Tattoo dyes, especially red dye, can cause allergic skin reactions, resulting in an itchy rash at the tattooed area. The worst part is this may occur even years after you get the tattoo.
3) Risk of Keloid formation. If you are prone to developing keloids, you should think twice before getting a tattoo. Although keloids are more of a result of tattoo removal, you are still at risk of keloid formation from the tattoo itself.
4) MRI complications. Though it happens rarely, tattoos may cause swelling or burning in the affected areas during magnetic resonance imaging (MRI) exams. In some cases pigments used in tattoos may interfere with the quality of the image.
5) Tattoo removal. Let us face it. Some people when they are young and impulsive do not think about how the tattoo will look when they get older. Or some people may later decide that they do not want the design anymore. Here comes the removal process. The bad thing about tattoo removal is it can leave a pretty bad scar in your skin and you will have to pay the added cost of removing it.