As tattoos become increasingly mainstream, more and more people search for a picture, symbol, or word they would be happy to have in their skin forever. Others who had this done look for ways to have these marks removed. Everyone knows that tattoos last for an entire lifetime and beyond, and most people assume because the ink is injected rather deep into the skin.
What Is a Tattoo Anyway?
Understanding why tattoos are permanent begins with an explanation of what a tattoo is. Professional artists use a machine that jabs a needle deep into a person's skin at a high rate of speed over and over again. This needle transfers a certain type of ink into the dermis, which is the lower level of skin that does not rejuvenate as quickly as the outer layers that are called the epidermis.
Why are Tattoos Permanent?
The assumption that these ink designs last forever because they are deep inside the skin is only partially correct. Because the ink is in the dermis instead of the epidermis, it sticks around for a long time because cell regeneration is much slower. Ink injected into the epidermis would not last very long because this top layer is constantly shedding old skin cells and making new ones.
The depth of the ink is not the only thing that makes tattoos permanent. The real answer involves your body's natural immune system and tiny cells called macrophages.
Here is what happens when you get a tattoo:
The artist loads the ink and turns on his machine. He moves it across your skin to make the design. The needle jabs into your skin repeatedly making tiny wounds for the ink to be injected through. Every time one of these wounds is made, your body responds.
This is the same natural response that occurs if you cut your finger or get a burn. Your body's self-defense mechanism kicks into gear and sends white blood cells, macrophages, and other things to the site of the damage and starts to repair it. That means every little needle hole and every tiny drop of ink gets attacked as an invader.
These cells called macrophages attempt to encapsulate the ink because it is a foreign substance that does not really belong in your body. However, ink is not a natural substance such as bacteria or a splinter that can be broken down over time. This means the macrophage can eat the ink molecule but cannot digest it and filter it out as waste for your bloodstream. These cells sit in your dermis holding onto the ink for the rest of your life. The natural fading of tattoos over time comes because the dermis does rejuvenate at a slow pace and these macrophages and other bodily defenders are constantly trying to chip away at the invading ink.
This entire process is in effect overall health or well-being. The tattoo heals over time and the immune response lessens. The tattoo remains inked into the skin forever unless laser tattoo removal breaks the ink down into smaller compounds the macrophages can deal with.