A tattoo is a form of body modification, made by inserting indelible ink into the dermis layer of the skin to change the pigment.

Know the risks

Tattoos breach the skin, which means that skin infections and other complications are possible. Specific risks include:

Allergic reactions. Tattoo dyes — especially red, green, yellow and blue dyes — can cause allergic skin reactions, such as an itchy rash at the tattoo site. This can occur even years after you get the tattoo.
Skin infections. A skin infection — which might cause redness, swelling, pain and a pus-like drainage — is possible after tattooing.
Other skin problems. Sometimes bumps called granulomas form around tattoo ink. Tattooing can also lead to keloids — raised areas caused by an overgrowth of scar tissue.
Bloodborne diseases. If the equipment used to create your tattoo is contaminated with infected blood, you can contract various bloodborne diseases — including tetanus, hepatitis B and hepatitis C.
MRI complications. Rarely, tattoos or permanent makeup might cause swelling or burning in the affected areas during magnetic resonance imaging (MRI) exams. In some cases, tattoo pigments can interfere with the quality of the image — such as when a person who has permanent eyeliner has an MRI of the eye.