Sebaceous cysts are small, non-cancerous lumps that form under the skin. They occur when a hair follicle or skin pore becomes blocked, leading to the accumulation of oil and dead skin cells. These cysts are usually painless and can appear anywhere on the body, but are most commonly found on the face, neck, and back. While sebaceous cysts are generally harmless, they can become inflamed or infected, causing discomfort. Treatment options include draining the cyst or surgical removal, especially if it causes pain or cosmetic concerns. It's important to consult a healthcare professional for proper diagnosis and care.