Generally, it's normal to experience some redness, soreness, and inflammation after getting inked. You may also experience itching around your tattoo, which is part of the healing process. However, if these symptoms persist or worsen, you could be dealing with an infection. The American Academy of Dermatology Association (AAD) recommends seeing a doctor if you have a fever, chills, rashes, or painful bumps. Also, watch out for any red areas that become darker or grow in size. 

The signs of an infected tattoo may vary from person to person. Furthermore, different viruses or bacteria will cause different symptoms, notes a 2016 review published in Deutsches Ärzteblatt International. For example, staph infections can lead to abscesses, pustules, papules, scaling rashes, or severe redness at the tattoo site. Infection with Pseudomonas aeruginosa or Streptococcus pyogenes may cause similar symptoms.

If left unaddressed, bacterial infections can develop into something more serious, such as toxic shock syndrome, heart inflammation, or sepsis, according to the above review. A thick, milky discharge at the tattoo site could be a sign of sepsis and requires emergency care. Severe redness, on the other hand, may indicate a kidney infection. You should also reach out to your doctor if you get multiple papules or abscesses. Note that some infections can occur days or months after getting a tattoo, warns the AAD.