A tattoo causes skin trauma to your body.
Healing differs for everyone depending on the location, size, and an individual's cleanliness and daily activities.

Because a tattoo is an open wound, it is prone to infection. Any time you open the skin, you expose yourself to scarring and infection.
You must also take care of your new tattoo at home, in addition to seeing a licensed and reputed tattoo artist.
This is a collaborative effort between you and your tattoo artist.