Getting a tattoo when your immune system isn't at 100% isn't a good idea. You're going to need your strength and your white blood cells to heal your tattoo, something your body won't be able to do if it's already doing battle against virus and bacteria. Not to mention the fact that it's very inconsiderate to bring your illness into the tattoo studio and risk passing the germs onto others, particularly your artist. If you have an appointment, call and reschedule for when you're feeling well again.