Skin cysts are small, closed sacs that can form under the skin. They are usually filled with a thick, oily substance called keratin. Cysts can develop anywhere on the body but are most commonly found on the face, neck, and back. They are generally harmless and often painless, although they can become inflamed or infected. Most skin cysts are benign and do not require treatment unless they cause discomfort or cosmetic concerns. If necessary, a healthcare provider can remove them through a minor surgical procedure. It's important to avoid squeezing or popping cysts, as this can lead to infection or scarring.