On this episode of the pod, we answer the question: How do tattoos work? We kick things off with a summary of the tattooing process and some statistics on how common tattooing is (broken out by demographics). We talk about the various reasons why people get tattooed -- some of which are cultural and/or religious. We summarize some history of tattoos as far back as several thousands of years ago. We then dig into the science of modern tattoos and detail the immune response that is triggered when we get tattooed (it's a complex process involving innate immune cells called macrophages). We spend some time discussing how tattoos may seem static and permanent but actually represent an indefinite, dynamic process. We discuss why the permanence of tattoos contribute to the challenges in removal. We of course detail some risks of tattoos including allergic reactions, skin infections, and the regulation (or lack thereof) of tattoo ink and potential safety issues. We wrap up with a brief discussion about how some people with tattoos are opposed to vaccines-- and touch upon the complicated psychology and cognitive dissonance involved in that thought process. PLEASE NOTE: The discussion and information provided in this podcast are for general educational, scientific, and informational purposes only and are not intended as, and should not be treated as, medical or other professional advice for any particular individual or individuals. Every person and medical issue is different, and diagnosis and treatment requires consideration of specific facts often unique to the individual. As such, the information contained in this podcast should not be used as a substitute for consultation with and/or treatment by a doctor or other medical professional. If you are experiencing any medical issue or have any medical concern, you should consult with a doctor or other medical professional.  Further, due to the inherent limitations of a podcast such as this as well as ongoing scientific developments, we do not guarantee the completeness or accuracy of the information or analysis provided in this podcast, although, of course we always endeavor to provide comprehensive information and analysis. In no event may Unbiased Science or any of the participants in this podcast be held liable to the listener or anyone else for any decision allegedly made or action allegedly taken or not taken allegedly in reliance on the discussion or information in this podcast or for any damages allegedly resulting from such reliance. Learn more about your ad choices. Visit megaphone.fm/adchoices