When getting a tattoo, ink is injected into both the outer (epidermis) and middle (dermis) layers of your skin, per Medical News Today. Since ink deposited into the dermis is what makes a tattoo permanent, ink on the epidermis causes the skin to shed as the tattoo heals. The healing process can be interrupted by excessive contact with clothing, sun exposure, and water. Non-sterile water sources such as oceans, hot tubs, and pools contain billions of bacteria that can lead to infection, dermatologist Jeremy Fenton, M.D., told Byrdie.

"If you allow chemicals (such as chlorine in a pool) or other substances in the water into the healing skin, it could ultimately affect the color and cosmetic result of the tattoo such as increased fading or discoloration," Fenton said. In addition to affecting the ink's vibrance, the risk of infection is quite high as well. "After any break to the skin, the natural immune defenses are impaired, and this increases the risk of infection," dermatologist Dr. Kathleen Welsh explained to Healthline.

The main culprit for such complications is Vibrio, a bacteria that largely inhabits open bodies of water. The CDC reports that Vibrio is responsible for nearly 80,000 illnesses and 100 deaths each year in the United States. The majority of these infections come from wound exposure to warm seawater, or even from consuming raw seafood. While avoiding oceans, lakes, and rivers are best, heavily chlorinated pools still carry the risk of bacterial infections.